OK. Just think rationally. There's no need to panic. Nothing's going to happen tonight. I'll just keep trying her mobile and as soon as I get through I'll explain in words of one syllable that she has to call this guy off and if she doesn't I will break her legs.

A low, insistent drumbeat starts playing over the loudspeakers, and I give a start of fright. I'm so distracted, I'd actually forgotten what we were here for. The auditorium is becoming completely dark, and around us the audience falls silent with anticipation. The beating increases in volume, but nothing happens on stage; it's still pitch black.

The drumming becomes even louder, and I'm starting to feel tense. This is all a bit spooky. When are they going to start dancing? When are they going to open the curtains? When are they going to—

Pow! Suddenly there's a gasp as a dazzling light fills the auditorium, nearly blinding me. Thumping music fills the air, and a single figure appears on stage in a black, glittering costume, twirling and leaping. Gosh, whoever it is, they're amazing. I'm blinking dazedly against the bright light, trying to see. I can hardly tell if it's a man or a woman or a—

Oh my God. It's Lissy.

I am pinioned to my seat by shock. Everything else has been swept away from my mind. I cannot keep my eyes off Lissy.

I had no idea she could do this. No idea! I mean, we did a bit of ballet together. And a bit of tap. But we never … I never … How can I have known someone for over twenty years and have no idea they could dance?

She just did this amazing slow, sinewy dance with a guy in a mask who I guess is Jean-Paul, and now she's leaping and spinning around with this ribbon thing, and the whole audience is staring at her, agog, and she looks so completely radiant. I haven't seen her look so happy for months. I'm so proud of her.

To my horror, tears start to prick my eyes. And now my nose is starting to run. I don't even have a tissue. This is so embarrassing. I'm going to have to sniff, like a mother at a Nativity play. Next I'll be standing up and running to the front with my camcorder, going, 'Hello darling, wave to Daddy!'

OK. I need to get a hold of myself, otherwise it'll be like the time I took my little god-daughter Amy to see the Disney cartoon Tarzan, and when the lights went up, she was fast asleep and I was in floods, being gawped at by a load of stony-eyed four-year-olds. (Just in my defence, it was pretty romantic. And Tarzan was pretty sexy.)

I feel something nudging my hand. I look up, and Jack's offering me a hanky. As I take it from him, his fingers curl briefly round mine.

When the performance comes to an end, I'm on a total high. Lissy takes a star bow, and both Jack and I applaud madly, grinning at each other.

'Don't tell anyone I cried,' I say, above the sound of applause.

'I won't,' says Jack, and gives me a rueful smile. 'I promise.'

The curtain comes down for the last time, and people start getting out of their seats, reaching for jackets and bags. And now we're coming back down to normality again, I feel my exhilaration seeping away and anxiety returning. I have to try to contact Jemima again.

At the exit, people are streaming across the courtyard to a lit-up room on the other side.

'Lissy said I should meet her at the party,' I say to Jack. 'So er … why don't you go on? I just need to make a quick call.'

'Are you OK?' says Jack, giving me a curious look. 'You seem jumpy.'

'I'm fine!' I say. 'Just excited!' I give him as convincing a beam as I can manage, then wait until he's safely out of earshot. Immediately I dial Jemima's number. Straight on to messages.

I dial it again. Messages again.

I want to scream with frustration. Where is she? What's she doing? How can I contain her if I don't know where she is?

I stand perfectly still, trying to ignore my thrusting panic, trying to work out what to do.

OK. I'll just have to go to the party and act normally, keep trying her on the phone and if all else fails, wait until I see her later. There's nothing else I can do. It'll be fine. It'll be fine.

The party is huge and bright and noisy. All the dancers are there, still in costume, and all the audience, and a fair number of people who seem to have come along just for the ride. Waiters are carrying drinks around and the noise of chatter is tremendous. As I walk in, I can't see anyone I know. I take a glass of wine and start edging into the crowd, overhearing conversations all around.

'… wonderful costumes …'

'… find time for rehearsals?'

'… judge was totally intransigent …'

Suddenly I spot Lissy, looking flushed and shiny and surrounded by a load of good-looking lawyer-type guys, one of whom is blatantly staring at her legs.

'Lissy!' I cry. She turns around and I give her a huge hug. 'I had no idea you could dance like that! You were amazing!'