'But I have no idea what it is,' I say at last.

'You can find out!' says Jemima. 'That's easy enough. The point is, you know he's hiding something.'

'There's definitely some kind of mystery,' says Lissy thoughtfully. 'He has all these phone calls he won't talk about, he rushes off mysteriously from your date—'

'He rushed off mysteriously?' says Jemima avidly. 'Where? Did he say anything? Did you overhear anything?'

'No!' I say, flushing slightly. 'Of course not. I don't … I would never eavesdrop on people!'

Jemima gives me a close look.

'Don't give me that. Yes you did. You did hear something. Come on, Emma. What was it?'

My mind flashes back to that evening. Sitting on the bench, sipping the pink cocktail. The breeze is blowing on my face, Jack and Sven are talking behind me in low voices …

'It was nothing much,' I say reluctantly. 'I just heard him say something about having to transfer something … and Plan B … and something being urgent …'

'Transfer what?' says Lissy suspiciously. 'Funds?'

'I dunno. And they said something about flying back up to Glasgow.'

Jemima looks beside herself.

'Emma, I do not believe this. You've had this information all this time? This has to be something juicy. It has to be. If only we knew more.' She exhales in frustration. 'You didn't have a Dictaphone or anything with you?'

'Of course I didn't!' I say with a little laugh. 'It was a date! Do you normally take a Dictaphone on a …' I tail off incredulously at her expression. 'Jemima. You don't.'

'Not always,' she says, with a defensive shrug. 'Just if I think it might come in … Anyway. That's irrelevant. The point is, you have information, Emma. You have power. You find out what this is all about — and then you expose him. That'll show Jack Harper who's boss. That'll get your revenge!'

I stare back at her determined face, and for a moment I feel a sheer, powerful exhilaration bubbling through me. That would pay Jack back. That would show him. Then he'd be sorry! Then he'd see I'm not just some nothing, nobody girl. Then he'd see. Then he'd see.

'So …' I lick my lips. 'So how would I do it?'

'First we try to work out as much as we can ourselves,' says Jemima. 'Then, I've got access to various … people who can help get more information.' She gives me a tiny wink. 'Discreetly.'

'Private detectives?' says Lissy in disbelief. 'Are you for real?'

'And then we expose him! Mummy's got contacts at all the papers …'

My head is thumping. Am I really talking about doing this? Am I really talking about getting revenge on Jack?

'A very good place to start is rubbish bins,' adds Jemima knowledgeably. 'You can find all sorts of things just by looking through somebody's trash.'

And all of a sudden sanity comes flying in through the window.

'Rubbish bins?' I say in horror. 'I'm not looking in any rubbish bins! In fact, I'm not doing this, full stop. It's a crazy idea.'

'You can't get all precious now, Emma!' says Jemima tartly, flicking back her hair. 'How else are you going to find out what his secret is?'

'Maybe I don't want to find out what his secret is,' I retort, feeling a sting of pride. 'Maybe I'm not interested.'

I wrap the chenille throw around me even more tightly, and stare at my toes miserably.

So Jack's got some huge secret he can't trust me with. Well, fine. Let him keep it. I'm not going to demean myself by grubbing after it. I'm not going to start poking around rubbish bins. I don't care what it is. I don't care about him.

'I want to forget about it,' I say, my face closing up. 'I want to move on.'

'No you don't!' retorts Jemima. 'Don't be stupid, Emma. This is your big chance for revenge. We are so going to get him.' I have never seen Jemima look so animated in my life. She reaches for her bag and gets out a tiny lilac Smythson notebook, together with a Tiffany pen. 'Right, so what do we know? Glasgow … Plan B … transfer …'

The Panther Corporation doesn't have offices in Scotland, does it?' says Lissy thoughtfully.

I turn my head, and stare at her in disbelief. She's scribbling on a pad of legal paper, with exactly the same preoccupied look she gets when she's solving one of her geeky puzzles. I can see the words 'Glasgow', 'transfer' and 'Plan B', and a place where she's jumbled up all the letters in 'Scotland' and tried to make a new word out of them.

For God's sake.

'Lissy, what are you doing?'

'I'm just … fiddling around,' she says, and blushes. 'I might go and look some stuff up on the Internet, just out of interest.'

'Look, just stop it, both of you!' I say. 'If Jack doesn't want to tell me what his secret is … then I don't want to know.'

Suddenly I feel completely drained by the day. And kind of bruised. I'm not interested in Jack's mysterious secret life. I don't want to think about it any more. I want to have a long hot bath and go to bed and just forget I ever met him.