Original subtitles

This programme contains some strong language

Newton's first law states that an object in motion...

..will remain in motion unless an external force...

..imposes a change upon it.

Similarly, an object at rest will remain at rest

until an unbalanced force affects it.

TABLET CLICKING

This is also known as

the law of inertia.

Hi, how was your day?

CLASSICAL MUSIC PLAYS SOFTLY

Is there any food?

Yes, there's a whole fridge full of food in front of you.

Yeah, but it's all olives and hummus and shit.

Something to actually eat?

Um, not every meal comes in a tray, Zach.

Some are made with what we humans call ingredients.

TABLET CLICKING

Don't eat all the cereal, please.

There'll be none left for the morning.

You can turn that off, you know.

Turn what off?

That stupid sound.

I like it.

It makes up for not having a proper bloomin' keyboard.

What are you actually doing?

I'm booking a smear test, if you must know.

Eurgh. Well, you asked.

HE SIGHS

It's giving me a migraine.

Don't exaggerate.

Just disable clicks!

I don't want to disable clicks! You disable clicks.

I have done.

Fine, then.

HE EXHALES

So, how was your day?

Did you get your results back?

Zachary?

Yes.

I got a B.

What do you actually want?

It'd be nice if we could just talk.

You can talk, I'm not stopping you.

I mean...a conversation,

a bit of back and forth,

I've been here on my own all day.

That's not my fault.

I don't think it's too much to ask to just sit

and have half an hour together of an evening.

Look, I'm not your boyfriend.

If you want to talk to someone, go on...Tinder.

I wasn't put on this Earth to make you happy.

You can say that again.

What's that supposed to mean? Nothing.

You want to bin me off like you did Dad?

Of course I don't.

And it was him who walked out, remember? Not me.

I don't blame him.

Look, if I could go back and do things differently,

I would do, but, Zach,

can't we, please, live together

without all of this constant argy-bargy?

Let's cut the beef, bro.

No-one says beef any more.

HE TYPES

THUD

SHE EXHALES

Oh, bloody hell...

Oh!

SHE EXHALES SLOWLY

Oh...

DOORBELL RINGS

Ah, yes, I, er...

I found this little - double T - bird

just outside your house. Right.

They fly towards their reflections in the windows, unfortunately. Huh.

Oh, dear.

Can we do anything for it, do you think?

Er, if you had a small - double L - box

and a quiet space, he might just come to.

Um, yes. Yeah, come in.

Oh, thank you.

Hopefully, it's not a concussion.

Sparrow, I think - double R.

Aw... They're tough old birds.

Poor thing.

Er, shall I, er...?

Oh, yeah. I'm Helen, by the way.

Oh, erm, Bob.

Bob Bliss - double S.

At least we know his insides are functioning. How?

Oh!

SHE CHUCKLES

Oh, here. Ooh!

Thank you, thanks.

It's very kind of you.

A lot of people wouldn't have cared.

Oh, well, I have a teenager, so...

..what's another feeble creature to look after?

Both of mine have flown the nest now.

Oh, lucky you.

No, I shouldn't say that.

So, is he the mathematician? He?

Er, your teenager - double E.

Oh, Zach, yes, yes. He's doing his A levels.

Yeah, maths, physics and chemistry, God help him.

Ha, great combo.

I did my PhD in physics at Cambridge a few years ago.

It's a fascinating subject, but a lot of it does depend

on the teaching.

PHONE RINGS

Excuse me. Yes.

Zach's teachers are terrible, so he tells me.

It's all - double L - relative, so, er...

Aw, this is my son, Zach.

Pleased to - double E - meet you.

FLUTTERING AND CHIRPING

Oh, bloody hell!

Come on. Oh!

There he goes!

DOOR CLOSES

SHE SIGHS

Zach, this is Bob.

Bob studied physics at Cambridge.

ZACH POURS DRINK

Aren't you even going to say hi?

Hi. Hi. Jinx!

Oh, you meant him say hi to me? Apologies, er...

Zach, you can speak now.

I know I can. I'm not eight years old.

FRIDGE DOOR OPENS

FRIDGE DOOR CLOSES

Right, as one uranium-238 nucleus said

to the other uranium-238 nucleus, "I've got to split."

He gets it.

BOB CHUCKLES

Yeah, it's nice to have met you, Helen.

Er, Zach, best of luck with your studies.

Hope that teaching improves.

I live close by, if you ever wanted to go through anything.

Wait, erm...sorry.

SHE LAUGHS NERVOUSLY

You don't do any tutoring, do you?

It's just that Zach needs to punch up his predicted grades.

Mum! Well, it's true!

Don't you want to get into a good uni, like Bob did?

She's so cringy, it's embarrassing.

I do have some spare time at the moment.

That is to say, I'm not fully - double L - engaged, erm...

Yeah, why don't I come round Thursday at six,

see - double E - how we get on?

And then if Zach thinks it's useful... Yeah, whatever.

Anything to avoid spending time with her.

Newton's second law of motion, in its simplest form,

can be expressed by the equation F=ma,

or force equals mass times acceleration.

It's why this car,

which has a greater mass,

will travel less far

than this car

when identical force is applied.

Oh, this is top-notch, Zach.

Well - double L - done.

Remember to put the, er, date on the top.

'62?

GROANS

Is that when you were born?

Yes, yes, I'm afraid I am rather old.

So why is F=ma a special case of the second law?

Well, it assumes that the mass remains constant.

It uses an inertial frame of reference.

Which means?

That there are no outside forces acting on it

that make it accelerate.

Very good - double O.

So, what outside forces are acting on you right now?

Gravity,

the Earth spinning,

you...

And the harder you're pushed, the further you can travel, yes?

BOTH CHUCKLE

OK. Thanks.

I, erm... I couldn't help but notice your tattoo -

double T, double O.

Yeah, er...

I only did it to piss my mum off.

And did it work?

She hasn't noticed.

That's how much she cares about me.

Oh, I think she does care, Zach.

I think she cares very deeply - double E -

but, as you know, objects with the same force do...

..repel each other. Repel each other. Yeah.

I don't want to pry, but, erm, is your father...?

Oh. He, er, lives in Singapore.

He's got a new family now, so...

..I don't really get to see him that often.

That must be hard.

For you and for your mother.

I don't have a problem with it.

She's the one that's fuckin' mental.

That's a strong word to use. You don't have to live with her.

Zach...

I'm... Dinner's ready!

OK.

CLASSICAL MUSIC PLAYS SOFTLY

That was lovely, thank you. Sure you don't want a glass?

No, no, I'm fine. Just one? Just a little bit?

Honestly, I'm fine. OK. Well, more for me.

Hey, I've got some homework for you.

It's the Grand National on Saturday.

Now, study the weights of the horses and the jockeys.

Try and use physics to pick us out a winner - double N.

You're teaching him gambling?

That's not very responsible.

It's not gambling if you know who's going to win.

Pick me one, Zach.

Pick your own!

Hm! Hm!

So...

What do you do with your days?

If you don't mind me asking.

No, erm...

I work part time as a book-keeper - double O, double K, double E.

A bit of a mouthful.

Yes.

Well...you could be...

..an egg batterer,

and then you'd say,

"Double G and T," every day! Double G and T.

You'd end up pissed!

SHE CHUCKLES

So, go on,

why do you do it, Blob...Bob?

Bob Bliss.

Stop interrogating him. What?

It's called conversation, Zach.

Listen and learn.

Go on, what's it all about? Double X, double L?

Well, I suppose - double P - it's, er, a mild form of OCD.

As a student of physics,

I was constantly trying to find patterns - double T -

in data and numbers,

and then in words.

Yeah, I find it calming.

I get it. When everything feels like it's unravelling,

and you've just got to hold on to something. It's like my clicks.

I need my clicks, and he doesn't want me to have them,

but I say, "No, they're for me."

Fuck's sake.

Zach, come back. Come back now.

Why?

So I can sit there and listen to you chat shit all night?

You're pathetic.

It's OK, honestly.

I dare say, it's just his hormones,

plus his dad walking out.

HELEN BREATHES DEEPLY

Up against my hormones,

plus red wine - not a good combo.

I'm sure we were all - double L - the same at his age.

Maybe if I could spend more time with him, I...

Why does nature do it, eh?

Give us the menopause

just as our kids are becoming feral monsters.

Can science explain that?

He's not a monster.

He's not.

He's just...an angry young man.

I'm so tired, Bob.

I know.

Right, I'd best be off.

Thanks for dinner -

double N.

And double F - off.

Double F - off.

A force is a push or a pull

that acts upon an object

as a result of its interaction with another object.

These forces are subject

to Newton's third law of motion.

For every action,

there is an equal and opposite reaction.

CLICKING

CLICKING

CLASSICAL MUSIC PLAYS SOFTLY

CHIRPING

CHIRPING CONTINUES

"Bob Bliss."

PHONE BUZZES

SHE SIGHS

Hello?

Um, speaking.

OK.

Today?

Um, yes, I can be there in about half an hour.

Right.

Right, er, I know you...

..you can't tell me, but is it regarding my test?

No, no. No, no, I understand.

I understand. Right.

Yeah, OK, thank you.

SHE SIGHS

MUFFLED: Hey, Mum, guess what?

You know Bob put a bet on the Grand National on Saturday?

Well, his horse only won.

He put 60 quid on at 33-1.

Sorry?

Bob won nearly two grand,

and he said he's going to give me half of it for my uni fund.

I don't want him coming round here any more.

What?

And you're not to take that money, do you hear?

Why? What's wrong with him?

We've got no idea who he is.

He could be anybody.

He's just...

..just some weirdo

who just turned up at our door one day.

What is wrong with yer?

Why do you have to ruin anything decent

that comes into my life?

It's for your own good. What happened?

Did you pathetically come on to him?

I haven't got time for this. You've never got time.

Whenever I try and talk to you, you're always doing something else.

Cooking, cleaning, washing your clothes,

trying to scrape together enough money to send you to university!

Well, don't bother!

I'm going to uni in Singapore, and Dad's paying for it.

Ha-ha-ha! What do you mean "ha"? He promised.

What? Like he promised to take you over for Christmas?

Well, fine, then!

Go running off to him and see what happens!

Well, at least he believes in me. You're such a fuckin' bitch!

Do you know...?

Sorry, Zach.

I'm sorry, Zach.

Zach...

Zach?

Listen, I've got to go to the...

DOORBELL RINGS

She's not here.

DOOR CLOSES

I've got some cash for you.

CHUCKLES

From the gee-gees - double G.

I'm not allowed to take it.

Why not?

Have you had another row with your mum?

Maybe I shouldn't have interfered.

Here.

I got her these.

HE CHUCKLES

Yellow roses - double L.

Those are her favourites.

Have you been stalking us?

Do you want to put them in some water?

OK.

FOOTSTEPS STOMP AWAY

KNOCKING ON DOOR

DOOR OPENS

Have you learned anything yet about the Doppler effect?

Double P, double F.

It describes the changing frequency of a wave

in relation to an observer

moving relative to the source of that wave - for example,

why a police siren is higher in pitch when it approaches -

double P - and lower in pitch when it drives away.

It's like time.

It drags when you're young, but when you're older...

..it flies by.

And you find yourself thinking about the things

you wish you'd done differently - double F.

What you'd say to yourself if you could go back 40 years

to when you were a boy.

What are you talking about?

In the future, it will be possible

to manipulate gravitational waves, as I said -

as you said - and harness the power of black holes.

Harness is double S. It doesn't matter. Listen.

What we thought was theoretical can actually be achieved, if...

..you get the physics right, and you did.

Did what?

'62 isn't when I was born,

it's where I came from.

Be kinder to your mother, Zach.

You'll only ever have one -

science'll never change that.

And yours...

..ours...

..she's not going to be around for much longer.

What do you mean?

What are you talking about?

She's dying, Zach.

By the time you go away to Singapore,

you'll have stopped speaking to each other,

and then it's going to be too late.

And believe me,

you'll spend the rest of your life regretting it.

You'll close in on yourself.

Your own kids will walk away from you.

And you'll understand too late

just how much she sacrificed for you,

how incredibly brave she was,

and that guilt will cripple you for life.

No, this is bullshit! You've got to believe me, Zach, please.

Please.

SHE EXHALES SLOWLY

SHE SOBS

Oh...

SHE SNIFFS

PHONE RINGS

I just need you to tell her I love her. Very much.

It won't save her, but it could save you.

Just a random act of kindness...

..so you can have my time again.

GUN COCKS

HE BREATHES HEAVILY

PHONE RINGS

Hello?

Zach, can you hear me?

What the fuck do you think you're doing?

Zach's my son. Who is this, please?

Oh, God. Er, please, Mrs Wilson, try to stay calm.

I think your son could be in grave danger.

The man whose phone this is, he...he's not to be trusted.

Do you understand? Do you mean Bob?

You mustn't leave your son alone with him.

But he's...

GUNSHOT

Zach?

Mrs Wilson... Zachary! ..let me speak to him...

HE BREATHES HEAVILY

Are you all right?

Oh!

Oh, it's OK, it's all right.

It's OK. SOBS: I love you, Mum.

I love you, too!

I love you so much.

Everything's going to be OK.

I promise.

Everything's going to be OK.

Thank you.

Thank you for coming.

Thank you.

Dr Wilson? Your daughter let me in.

Call me Zach, please. Everybody does.

It was a lovely service. Thank you.

I'm sure me mother would've said it went on a bit too long,

but then a lot of people said that about her, as well.

How old was she? 93.

Ah, well,

that's a very decent age, even by today's standards.

She was a tough old bird.

Strange being back in here without her.

Sorry, can I, er, offer you a drink?

I'll have a coffee, please, yes.

So, me daughters were telling me you have a Youku channel?

Yes. I do little science videos for children - pretty basic stuff.

And you wanted to interview my mother?

That's right. I wanted to hear in her own words

what she could remember.

She was one of the first people to try your anti-cancer serum

back in '29.

It was a long time ago. Well...

Time is relative, so...

Sugar? Yes, please.

So, you're an actual scientist, then?

You're not an actor in a white coat?

Ha, yes, I do dabble.

In fact, this could've been me,

world-famous Nobel Prize-winner,

but you cheated me out of that, didn't you, Zach?

In another time, we were partners, you and I.

We developed the Wilson-Brann wormhole together.

It was a game-changer.

CHIRPING

It made us billions.

It's gone. It's gone, it's gone, it's gone!

But because, in this timeline,

you never left to study physics in Singapore,

you never came to Cambridge

to research black holes, and so we...never met.

You devoted your life to chemistry,

oncological research.

I ended up doing Youku videos as Dr Brann the Science Man.

I'd like you to leave now, please.

And then, one day, I was clearing out my spam folder

and I found a video message

I had apparently just emailed to myself.

I must've realised that I didn't have long

before that version of my life ceased to exist.

VIDEO: You can go back in time...

I always felt I was living the wrong life.

The life you stole from me...

..I want it back.

Where is it? What?

The Trans-Temporal-Telegraph.

Our time machine.

The one you used to visit yourself as a boy.

That was just junk. I got rid of it.

I don't believe you. It's true.

Bob was insane.

No.

We're going back, Dr Wilson.

It's time to reset.

No, please.

Please. My mother... Fuck her.

I'm not prepared to be your collateral damage.

Oh, bloody hell...

TYPING

THUD

Oh!

SHE EXHALES SLOWLY