'oh dear!' i say sympathetically. 'well, i'm sure they were all necessary. if it's a matter of your health ...'

'i've never known a medical like it. that doctor made me run for an hour.' he looks incredulous. 'and there were six questionnaires, all repeating each other. whoever devises these things is an utter imbecile.'

davina told me earlier that luke was the stroppiest patient she'd ever had and that he'd given her a lecture on how inefficient and time-wasting her medical was. which is fair enough, given that she spun it out for four hours longer than normal.

'poor you.' i stifle a laugh. 'well, i'm afraid a whole pile of paperwork arrived for you to read urgently ...'

just in case you thought you were escaping for a minute.

i drag over the box that bonnie couriered round this afternoon, which is full of contracts and letters. that should keep him busy.

'let me get online.' luke perks up. 'is this my new laptop? excellent.'

i feel prickles of alarm as he unpacks it from its box. even though i know it's safe. they promised me. sure enough, after a little while, luke curses again.

'bloody thing's got no internet access!' he jabs at it a few times. 'what's wrong with this bloody server?'

'oh dear,' i say innocently. 'never mind. well, why not just deal with the paperwork? you can sort out your laptop tomorrow. have you eaten? would you like some risotto? janice brought some round.'

i'm just heating up the risotto in the kitchen when i hear luke's phone ring.

'luke brandon.' i can just about hear him answer. 'oh, sage! hello there. just wait a minute ...'

the living-room door is shut. damn.

i hesitate for a moment - then tiptoe through the hall and press my ear to the door.

'well, i'm sorry to hear that,' luke is saying. 'of course you're our number-one priority. sage ... listen, sage ... no one's saying that, sage ...'

yes! she's obviously giving a brilliant show. well, of course she is. she's an actress.

'well, of course i can ... 8 a.m.? at pinewood. ok, fine. i'll see you there.'

there's silence from the living room, and i wonder whether to tiptoe away, when i hear his voice again.

'bonnie? it's luke here. just had sage seymour on the phone. i'm afraid she's confirmed every suspicion i ever had. nightmare woman. she's insisting i come to her movie set first thing tomorrow.' he pauses. 'i don't know why! this has come out of nowhere! she was talking gibberish about press statements and strategies, she seems totally self-obsessed, paranoid we're not taking enough interest ... anyway, i'll call you when i'm on my way back to the office.' he lowers his voice, so i have to press even harder against the door to hear. 'thank goodness i didn't tell becky. something told me to wait until we knew it was going to work out-' he breaks off. 'no! of course i haven't mentioned that to becky yet. it's only a possibility. we'll cross that bridge when we need to.'

my ears prick up. what's a possibility? what bridge?

'i'll see you tomorrow, bonnie. thanks for that.'

shit. he's coming. i dart back to the kitchen, where of course the risotto has burned at the bottom of the pan. i'm briskly stirring the burnt bits into the rest when luke comes in.

'i've got an early start tomorrow, by the way,' he says guardedly. 'seeing a client.'

'have some food, then.' i put a plate down in front of him, like a perfect, unsuspicious wife. 'big day tomorrow. your birthday, remember?'

'shit. of course it is.' alarm briefly crosses his face. 'becky, you haven't made any plans, have you? you know we've got this big company training programme? it'll go on into the evening, i don't know when i'll be back ...'

'of course.' i manage an easy tone. 'no worries! we'll do something nice on saturday.'

oh god. i can't cope. my mouth keeps twitching with faint hysteria and i feel as if thought bubbles must be floating above my head.

there's a marquee outside the window! it's your party tomorrow! we're all in on the surprise except you!

i can't believe he hasn't guessed. i can't believe i've kept it secret for this long. i feel like there's only the thinnest curtain hiding everything in my brain and any minute he'll sweep it aside and see the lot.