Original subtitles

Who can remember what we learned last lesson about chain reactions?

It's like dominos, sir. That's right.

It's like dominos.

When just one molecule is activated, it can cause a reaction,

which in turn releases more unstable molecules.

They then trigger further reactions, and so the chain gathers momentum.

See how it's branching and growing as it feeds itself.

L is the angular momentum quantum number. Angular momentum.

L tells you the type and shape... Tells you the types of the orbitals.

ML is the magnetic quantum number. Quantum number.

Okay.

Oh.

Today we're going to take a look at the first chain reaction ever discovered.

Hydrogen and chlorine.

All you need to trigger this is UV light, which you get by burning

But once the chain is in motion, it's unstoppable.

every time, sir.

James.

The flat's looking a bit tired.

This is what you're doing with your day off. Sprucing out the bachelor pad.

I'm not sprucing.

Marine dream bloom night.

Haven't you got somewhere else to be? I don't remember you booking the day off.

Community partnership seminar, 3pm.

Enjoy.

I wasn't sure what you'd want to do. The garage said they could fix it. Just get

rid of it.

The interview isn't that bad, as long as you know your chemistry.

Make sure you do some mock interviews with Mr Drew if you do decide to apply.

They basically ask me all the same stuff.

Glad to be of service.

Anyone else?

Is it loads more work than A -level?

Well, it's a big step up, obviously.

But it's all right.

Most of the time.

Good.

Well, I think we should give Adam a round of applause to say thank you for

coming back.

Erin had this bean plant.

She was supposed to grow it over the holidays and measure it every day.

Mum carried on watering it for weeks afterwards.

And I just kept thinking, how is this thing still alive?

How is it possible that this stupid little plant can keep on living and

We both realise how

difficult this must be.

But do you feel able to let Richard respond?

Rachel, I need you to know that your sister and what I did will stay

with me forever.

If I could do anything to change what happened... All you had to do was think,

I've had a nice boozy lunch. Maybe I won't get in my car this afternoon.

How hard is that?

I know I can't expect forgiveness.

But prison has strengthened my faith.

And as part of my recovery.

Your recovery?

Of course.

That's what this is about.

Rachel, please. Forget it.

Three years out in one. It's a joke.

You all right, okay?

I'm sorry.

I'm so sorry.

I know you don't want to hear it, but I think that was brave.

It was selfish.

Things will get easier, I promise.

With God's help.

Yeah, I'm not sure that I've got it right.

No, that sounds fine. As long as the juice is drunk, then you're OK.

Anything else?

Yeah, then leave it on a hot dish for 20 minutes to relax.

Thanks.

As long as one of us is relaxed.

Well, wish me luck.

Good luck.

Beautiful place, this, isn't it?

What we got?

Deceased is Professor Richard Seeger, biochemist, fellow of Benison College.

He was released from prison yesterday after serving a year for causing death

dangerous driving.

No signs of a break -in. Body was discovered two hours ago by his wife,

Reverend Martha Seeger, crushed under his own car.

Bloody hell.

I know.

You do read about these freak accidents, don't you?

No, sir. This is not an accident.

The car must have accelerated pretty hard to churn up this much gravel.

I can't get to them properly, but the first thing I'm seeing under here is

multiple flaying injuries where the wheels have taken the skin away.

Jack, he was knocked down and then driven back over several times. All

all right. You can see it wasn't an accident.

She's giving humanity the benefit of the doubt, for one.

She left here the first time at around eight, if that's any use.

Sorry, who left her there?

Rachel Cliff.

The girl who killed my husband.

Erin Cliff was the young girl involved in the fatal road accident with

Seeger. Rachel was Erin's sister.

And the jag outside is the same car that killed Erin.

It was my fault.

Rachel and her mother were on their own, and I thought I could help.

What do you mean?

I persuaded her to meet Richard.

I honestly thought it would be good, but she left here angrier than ever. She

must have taken the keys from the hall and come back.

Can you take us through what happened in between Rachel leaving here and you

finding Richard's body this morning?

We had an early night. He was exhausted.

Then this morning when I took him his tea in bed, he wasn't there.

I thought he must be pottering in the garden.

And then I found him.

How was your relationship with your husband?

Good.

We were happy.

But you didn't realise he wasn't in bed until you took him his cup of tea.

So you weren't sleeping in the same room?

Well, Britain makes things difficult. He needed some time to adjust, so he slept

in the spare room.

And where did you sleep last night?

The main bedroom.

The one on the front of the house with the window open?

That's right.

And you didn't hear anything?

No, not a thing.

Some people do sleep very deeply.

So deeply they miss a violent murder going on outside their window.

How's it looking, Laura?

Like a man under a car at the moment.

I won't be able to judge Luvidity till we get him out from under there. But

there's early rigor mortis in the neck and jaw, so dead maybe five, six hours.

There's something else, though.

Small scratchings in the bodywork with what seems to be the same colour paint

the end of his keys.

It's a number.

500.

It looks like Seager wrote that as he was dying. Was that possible?

Depending on its injuries, it might have been possible.

Why 500?

Isn't all these search adults for him quite famous for a scientist?

What did he discover?

Well, it seems to be more about his promotion of the idea of intelligent

that the complexity of the universe is down to the existence of an intelligent

creator. We know what it is, Sergeant.

Sorry. Anyway, Tsega was a leading proponent. He ran a lecture course

that God and science aren't mutually exclusive.

Sorry I missed it.

So, explains why he was married to a vicar.

Do you know what she was claiming? She slept through the whole thing.

You're not convinced?

Not for a minute.

I hope none of you sleep through that kind of racket.

If you find out, do let me know.

What's she mean by that?

I think she's implying you're a snorer, sir.

Marl always said it was more of a snuffling.

Maybe she was being kind.

It's strange, you know, after all these years.

Good strange?

Yeah.

Really good strange.

So you should have ended up with something that looks like this.

With the intermolecular hydrogen bonding shown by the dashed lines.

So, is everyone all right with that?

Any problems at all?

Adam, do you want to hang on for ten minutes at the end?

Right, let's move on to diphosphide linkages and other covalent bonds.

There you go. Thank you. You're welcome.

Rachel Cliff?

Yes? D .I. Lewis, D .F. Hathaway, Occupantship Police.

Could we have a word?

Oh. What about?

I'm my mother.

We understand that you've had dealings with Professor Richard Seeger.

Dealings? I've not heard it called that before.

He killed my daughter, if that's what you're getting at. He was found murdered

at home this morning.

Oh.

There you go.

Maybe I'll buy a lottery ticket later.

Mum!

Under the circumstances, we do need to ask you some questions.

Ask away.

In particular, Rachel, we need to speak to you about your contact with the

professor last night.

I'm sorry.

You promised me.

You promised me you wouldn't go round there. Adam said he wouldn't let you go

round there. Martha thought it might help. Oh, well, if Martha thought...

Rachel, is there something we can talk in private?

I think it'd be enough, wouldn't you, them taking my little girl, but...

Then they had to try and take Rachel, too.

Phone calls and letters and come to our church, come to our house.

And now, now we've got the police round here asking questions.

If you and your daughter would be willing to give a DNA sample and print

at the station.

Fine. Whatever.

Thanks.

It would also be helpful to know where you were in the small houses, Mum.

I was reading Heat magazine in the waiting room of A &E.

I managed to twist this when I was putting the bins out.

Excuse me.

Liam?

Everything OK?

When was this?

It was weird. It was like she was his wife, so I hated her.

But it also felt like she understood.

Like I could say things to her that I couldn't say to my mum.

She told me about last night.

I finally realised it was all an act.

She was just pretending to be nice so I'd forgive her husband.

She said that you were really upset when you left. Where did you go after?

Went back to my boyfriend's. Got trashed.

Where were you during the night?

Still in my boyfriend's room in town.

Adam Tibbett. He's a first -year at Benderson College.

We went to school together.

Can anyone else confirm that you were there all night?

Why?

What's she been saying?

We just need to establish your whereabouts.

She thinks I killed him, doesn't she?

Well, you know what?

I wish I had.

Hang on a minute.

I just need a word.

Trans ominous. I thought I was going to say to you a prospect.

Yeah, well, I don't usually offer these to my suspects.

Come on.

My old granny used to pay me in giant chocolate biscuits for mowing a lawn.

Sounds like an excellent trade -off.

Wasn't bad.

Stayed with her almost every year.

Little bungalow out in Whitney Bay.

Do you know when I last saw my grandson?

Christmas, for a day and a half.

Took him a toy fire engine that he already had.

Take a week off, go up there.

Apparently, he's been in hospital the last three days.

Lynn just phoned me a couple of minutes ago.

You all right?

Well, not in hospital.

Back home running riot, according to his mum, but... Thing is...

She didn't even call me until that whole thing was sorted.

Didn't want to worry me.

I don't even feel part of my own family anymore.

Anyway, that's it now.

Been going on about retiring for ages.

Time I chucked it in.

Put my family first.

And Laura, if she'll let me.

I'm sure she will.

Thing is...

When I go, there'll be a DI job come Vegas.

You should apply for it.

Set up a meeting with Innocent. Let them know you're interested.

Yeah, thanks. I don't think I'm... Come on.

You're more than ready.

No, I don't mean that. I mean, it just wouldn't feel right if you went for me

stay. Well, I hate to break it to you, but you're a bit too young to retire

me.

Much as I'd like us to have an allotment and a nice little sailing dinky to go.

Well, I've heard worse plans.

Seriously, though.

You're ready to go and do this on your own, so go and do it.

I'll think about it.

Think about it?

Mm -hm.

Well, why don't you think about it on your way down to the prison?

Find out if Seeger had made any enemies while he was inside.

I'll see what I can dig up at this college.

Now, I'm sorry, but the exams are two weeks away, and you're still struggling

with basic concepts. But I'm working as hard as I can. Why don't we see how

these exams go and then talk again, okay?

But it might be that you're better suited to another course.

At another university.

Detective Inspector Louie.

I need to speak to you about Professor Seager. Yes?

I'm afraid I have some bad news.

He's dead, I know.

What do you want from me?

Well, I've told you you're the master here, and I was hoping you could give me

some information about his academic life, if it's not too much trouble.

No, no, not at all. Forgive me, I'm a bit, uh... Do you know anything about

century roofs?

Not my specialist subject, to be honest. Nor mine.

Turns out they're expensive.

Apparently ours is on the verge of collapse.

I'm sorry to hear that.

Well, how can I help?

Did Professor Seeger have any enemies that you were aware of? Well, the usual

intellectual squabbles, but nothing serious that I can recall.

And what was the plan for after his release? Was he coming back to work?

that was a difficult one. Richard had a brilliant scientific mind, truly

brilliant, but...

With fellowship comes moral responsibilities. We held a ballot, and

vote was to revoke his fellowship and promote Stella to his chair of the

chemistry role.

Stella. Dr. Stella Drew, Richard's prodigy. I think she's the best person

could speak to. Knew him much better than I did.

Any idea where I might find her? You could try her rooms. Old quad, top of J

staircase.

Dr. Drew?

D .I. Lewis, Oxfordshire Police.

Hello.

Stella's at work.

Is this about Richard?

Yes. And Martha phoned us this morning. Sorry, you are?

Carl Drew. I'm Stella's husband.

That's the last time I let my year nines loose with the iodine. Please, come in.

So you knew Professor Seeger?

He taught me and Stella when we were undergrads here.

Stella decided to stay and then I was kind of stuck with him.

Not his biggest fan.

No, he wasn't that bad, I suppose.

Just a little bit, you know, Oxford.

If you weren't ridiculously gifted like Stell, you basically were invisible to

him. How well did you know his wife?

Far too well.

She's Theda's best friend.

One of mine, too.

So we've been treated to the ongoing saga of their marriage for years.

The saga?

It's been dragging on forever.

Richard filed for divorce.

a couple of years ago.

Martha was fighting it and he never quite moved out.

I think she was almost glad when he was sent to prison.

At least it meant he wouldn't leave her.

Her Stella knows more about it.

Greenway lab.

Right, Hock.

She'll be there till late.

James, see what you can find out about a Dr. Stella Drew of Benison College.

I meet me in the science park in Benin, now.

Can we make it more like three? I've got a bit sidetracked.

Huh? What by?

Stapleton did some digging and came up with years of debate in the scientific

press between Seeger and the master of Benetton College, Graham Yardley.

I just met him.

The cagey. Well, I'm not surprised. He's been waging war on Seeger since the

80s, arguing that his Christian teaching should be banned from universities.

Really? I don't think he got around to telling me that.

How's that thinking going?

Have you fixed up a meeting with him or something? Nope.

But I managed to get in touch with Seeger's prison officer.

Changing the subject, okay.

Apparently Martha forgot to tell her that he was a raging alcoholic and had

for a decade.

He had a drink problem.

Are you sure about that?

Everyone in the prison says the same. He spent his days praying, going to

alcohol recovery meetings and talking about how to lead a better life when he

got out.

Visitors? Only Martha the entire year, with the exception of one visit ten days

ago from Adam Tibbett.

Rachel's boyfriend.

Interesting.

Where are we?

Greenaway Labs.

I realised after you called I'd come across Stella Drew before I had her

interviewed on Woman's Hour a few months ago.

Woman's Hour?

It's an excellent programme. You should download the podcast.

So what does she have to say for herself on Woman's Hour?

It's not impressive.

Actually, she made some sort of breakthrough in Alzheimer's research

was still a postgrad, became a fellow in her early 20s, campaigned for more

women in science.

God, one of them.

What, feminist?

No, overachiever.

They make me uneasy.

He was my mentor for 15 years.

Everything we're doing here is down to him.

It's research into dementia, is that right?

Into Alzheimer's, yes.

My particular research stems from my doctoral work on the amyloid hypothesis.

The question of whether amyloid fibril formation is the cause of

neurodegeneration or if another protein such as... I lost you at hypothesis,

didn't I? You might have.

Never mind.

Well, so let's get to the point. Carl called. He thinks he put his foot in it

about Richard divorcing Martha.

And now you want to know whether or not my friend killed her husband.

We wouldn't have put it quite like that.

Presumably it's one of your hypotheses.

I can tell you that she isn't capable of it.

I've asked her to stay with us until she's ready to go back home, and I

have done that if I thought she was a risk to anyone.

Surely you should be speaking to the family of the little girl from the

accident. We have to keep an open mind for the moment.

You run Professor Seeger's research team now, is that right?

Yes. And you were promoted to chair of chemistry.

Only thing I stood to gain from his death.

Just... Establishing the fact.

That's fair enough.

Well, the facts are that, yes, I have now taken over his positions, but that

happened while he was in prison. And when there was a bit of controversy

whether or not he should be allowed to stay on at the college, I voted in his

favour.

Any way we can confirm that?

The Master Secretary should be able to show you the ballots.

It wasn't anonymous.

Fine. Thank you.

Does the number 500 mean anything to you? A measurement, perhaps, or a

to a chemical?

500?

No. Not particularly. Why?

Just part of our investigation.

Could you keep it in mind? Let us know if anything occurs to you. Of course.

Surely if Seager wanted to point us towards somebody in the chemistry

department, he'd have written their name, not just their extension number.

There could be a connection. If all the phones begin with extension 500, then

there might be a voicemail on one of them. I could ask the university to

me access.

Are you proposing phone hacking, Sergeant?

It's not phone hacking, if you ask nicely.

From the degree of hypostasis and the decreased fluid pressure behind the

I put time of death at 2 or 3 a .m.? What?

Nothing. Carry on.

The contusions, multiple fractures and tyre impression are all consistent

with... I'm sorry, I'm not... Oh,

God, sorry.

It's all a bit odd now, isn't it?

You and me and... I don't know, some of our best times together have involved a

mangled corpse.

Yeah, that's just my point. It's not normal, surely.

We do have to work together, Robbie.

I hope this isn't going to be a problem.

Well, I've been having a think.

You know, I'm always banging on about retiring.

What would you say if I just did it?

I'd save up bloody time.

Would you?

Really, you'd be all right about being with a pensioner.

Would that pensioner have my dinner on the table when I get home and rub my

for me till I can retire too?

I'm sure he would.

Then I'd love it.

Reverend?

Martha!

Hello?

Oh. Could we have a chat?

Is there any news?

Why are you lying to us?

I'm not sure I know what you mean. Why didn't you tell us that your husband was

an alcoholic?

Because he was in recovery.

And that he'd asked you for a divorce?

I didn't say anything because it was all in the past.

Richard filed the petition before he went to prison.

But only because he wanted to protect me from his drinking.

He did it because he loved me.

Had he withdrawn the divorce petition?

No.

Would have done. I'm certain.

If there's anything else you haven't told us, Martha, we really do need to

There's nothing.

Must have been difficult.

To sit by him through the alcoholism, through the accident, through prison.

And at the end of all that, to find that he's still filing for divorce.

What are you saying?

Did he reject you?

Did you snap?

I went to his room and tried to comfort him.

He pushed me away.

He always said he was leaving because of the drink.

No other reason.

So when he was released and he was doing so well, I thought I was getting my

husband back.

But then last night he told me I wasn't.

He said the drinking wasn't just about work.

It was about me.

I went upstairs and I lay in our bed on my own until I went to sleep.

I didn't expect to be sent, but I think I believe her.

You're just a sucker for a dog collar.

That's true, but if she did snap, why would she use the car? It's a bit

elaborate. Well, maybe she was driving away and he was trying to stop her.

Look, I need to check on her getting on down at the station. Why don't you try

and track down this Adam Tibbet?

See if he admits to visiting Siga in the prison.

Cheers.

Good little artist, wasn't she?

Erin. Yeah, she was brilliant.

I gave her a paint set for her eighth birthday and then the pictures just kept

on coming.

So, um...

Tell me what you can about Professor Seeger. Did you know him before the

accident?

Well, I met him once in my interview.

And the strangest thing was, I actually liked him at the time.

Did you see him again after?

Not at college, no, no, no. He was already in prison by the time I came up.

then... Then he started writing these letters to Rachel. And it was getting

creepy. Like, every week going on. Wanted to meet up as soon as he got out

prison. So I went to see him.

Asked him to leave her alone.

And what did he say?

Oh, he promised he'd stop.

But by this point, it was too late.

Martha had already gotten into her head and persuaded her it was a good idea.

So did you go with Rachel when she went to Seusega last night?

Yeah, I waited outside.

What did you do after?

We came back here. Hasn't Rachel already told you all this? I need to confirm

these things with you. Where were you between the hours of 2 and 3 a .m.? Why

are you asking me that?

I'm not accusing you of anything.

I was asleep right there with Rachel. Look, I've got my exams in less than two

weeks, and I'm really behind with my revision, so... Good

luck with that. I'll try not to disturb you again.

Robbie,

what's this from HR about your pension forecast?

Ah, I was going to talk to you about that once I was certain.

You're going?

Well, I'm giving it some serious thought.

Something happened I should know about?

Old age.

It happened when I wasn't looking.

Well, probably when I was sitting here trying to figure out stuff like this.

Oh, don't be so bloody maudlin. You love it, really.

Yeah, I love... My kids. I love my grandson.

I quite like Laura.

But it'd be nice to spend some time with them.

Well, then I'm glad you're thinking about it.

That's not the same as believing for a second you'll actually go through with

it.

But it's reassuring to know that one of us looks forward to going home at night.

So, how's the current puzzle looking?

Well, house to house didn't come up with anything, and...

Seeger's plated too remote for CCTV to be much use.

Well, maybe Hathaway's solved it and you can get off early.

Alas, not one, but the phone company got back to me. Seeger took a 30 -second

call from a pay -as -you -go mobile at 2 .20 this morning. They can't trace the

pay -as -you -go, but they can say that it was only ever used to make that one

call. So the killer called Seeger to lure him onto the driveway.

And it was someone he'd agreed to see in the middle of the night.

An affair?

That's what I was thinking.

When was this?

A screenshot from the John Radcliffe.

Shows that Debbie was in A &E all night.

Well, that's good.

Just as useful to know who it isn't.

What about this 500, the thing he scratched into the paintwork?

Eight phones in the lab, all have extensions beginning 500. None of the

left on them seem significant.

Nothing more concrete?

Not yet. I've got two teams going through his papers, his computers, but

nothing.

It must be something else.

Come on, Cambridge.

You'll start at a ten.

Find out what it means.

Do you fancy a pint?

Yeah, well, usually.

It's just... Don't worry about it. We'll do it another night.

You know what, though?

Mum?

James wants a word, if you've got a minute.

No doubt.

Someone tried to impress.

Yeah, thanks for that last night.

How'd it go?

It didn't.

If it's all right with you, I'll decide when I go for promotion, if I go for

promotion. OK.

Message understood.

Yardley's secretary got back to me with the results of the fellows' ballots,

said it was telling the truth. She did vote for Seagate to stay on.

Oh, right.

So she wasn't after his job.

Yeah, but the weird thing is, Yardley also voted the same way. Now, if he

objected to Seeger's beliefs that much, you would have thought he'd take the

opportunity to get rid of him. Robbie.

Willard. Did I forget something?

No, but the lab have just called. They've got the first DNA results from

car. Oh, anything helpful?

Well, there are dozens of DNA profiles in there. His wife, his colleagues, and

some that we can't identify.

But one of the hairs taken from the driver's headrest had some follicle

attached. And the DNA from that follicle is an exact match for Rachel Cliff.

You're pulling... Your pipe is on the way.

Come on.

We're hoping for another chat with Rachel if she's around.

Does it look like she's around?

Any idea where we might find her? It's actually quite urgent. She's 18.

I don't keep tabs on her. Shall we try her boyfriend, perhaps? You can try

wherever you like. She's not going to say anything she hasn't already said.

OK. Thank you.

This is important. Are you absolutely sure you've never been inside Professor

Seeger's car? No, I told you. Why would I want to go anywhere near that thing?

In that case, we'd like you to come down to the station with us and answer some

questions on the tape.

What? You're arresting her.

You can't. You can't arrest her. I'm not arresting. No, but we do need your help

with our investigation.

I haven't done anything.

And in the long run, it would be better for everybody if you do that

voluntarily.

The police are in there with you. There's no problem. They just need to

the... Sorry to interrupt, but the master's asking if you can pop down to

main quad.

Thanks. Tell him we'll be there in a few minutes.

He says it's urgent.

Don't go anywhere.

Call her.

Now.

It would appear we have a situation with our roof.

What kind of situation?

I think it's best you take a look, but your discretion would be appreciated.

Tell him.

This gentleman will show you.

This way, gents, if you would.

How long has this been up there?

Sir?

Hmm? Maybe it wasn't a number that Seager was scratching into his car.

There's a name.

Multiple fractures, including the skull. She was an exchange student from South

Korea. It's me.

Call me as soon as you get this.

Look, tell me what they said.

Are you saying that Reverend Seeger's been pulling your hair out? I don't want

to hear sob stories. I want to know what happened that night.

What has the fact that I went out with Su Ming 15 years ago got to do with

Seeger? I should never have left her in that house on her own.

Seeger's blood is on Su Ming's suitcase.

Under the handle.

I knew there had to be a connection.