For me, of course, the jingly-jangly message is particularly poignant. How jolly can you be, after all, when you're being stalked by e-mail by someone called "The Tagman"? Since I discovered my tormentor can see me at my desk, so is on the trading floor, my life has been fraying at the seams. At night, the slightest sound wakes me - assuming I've managed to sleep in the first place, that is. I take taxis everywhere, even more than I did before. And at work, I feel uneasy with most people.
"I know I'm being absurd suspecting everyone," I tell Laura. "Don't be offended but, for a moment, I even thought it might be you."
"Of course you did," Laura replies calmly. "You're upset and frightened. I won't take it personally. But I do think you ought to tell someone about it - Rory, maybe, or personnel."
But Rory doesn't want to know. Even worse, he seems to think it's funny. "Been breaking some man's heart again, have you?" he laughs. "Or is someone fed up with all those nasty things you keep saying about Liffe traders?" Human Resources are even less helpful. They tell me that because my stalker is using a web-based address they are harder to trace, and would I like "victim counselling" instead?
"So you see," I tell Laura, "either I have to laugh it off macho-style or fall apart weeping fragile-girlie-style. But as I'm a grown-up woman, what I really want to do is find out who The Tagman is and make them stop. Who can it be?"
I have several theories, many formulated in the long, dark hours of the night when I'm unable to sleep. Obviously, it's not a woman: no woman would do this to one of her City sisters, I'm sure.
No, this is all a power game by some testosterone-laden boy who thinks I've taken the job he should have. Or it's someone with a xenophobic streak who thinks that Jaap has the job he should have, and who's trying to get at him through me. After all, several of the messages have threatened to damage his pretty face if I don't stop dating him, so it's a plausible explanation.
Still the messages keep coming, two or three a day, each one nastier and more menacing. I read them all, then wish I hadn't - only I want to be brave, you see, and that means not running away from problems. But my body has no truck with this, and has simultaneously killed my appetite and given me a perpetual thumping headache. As a pre-Christmas diet, it's distressingly effective, but not quite so good for the brain power.
So it takes me a while to notice the messages have stopped. Even though it's late in the day - Mrs Hughes has already done her afternoon run with the coffee trolley - nothing nasty has arrived today. I mention it to Laura, who says "Hmm" and looks thoughtful.
"There's a lot of flu around at the moment, of course," she says. We stare slowly around the room, trying to spot the empty chairs of absentees, but they're few and far between.
"Well, the only person who's away that I can see is Kirsty, and it's hardly going to be ... " I pause, my mouth suddenly dry. Laura and I gaze at each other in shock. It couldn't be. Or could it?