Tuesday:

During breakfast, I am surprised to be addressed directly by my wife. "Look at this," she says, pointing to a page in the Telegraph. "That mobile I bought you for your birthday last year, it's top of this league table. Isn't that good?" Yes, I say, but what precisely has it won? She doesn't reply, and only when she moves on to the Mail do I get the chance to check. The Ericsson T28 is top of the mobiles, I read, for radiation emitted.

Wednesday:

Today a gradual change - a strange sense of disorientation and remoteness - is more noticeable, while the short-term memory is appalling. I have ascribed this to the aggregated effects of drink and age, but I'm not so sure. When a professor from Charing Cross hospital, a charming man whom we met once in the summer, rings to ask us to a party, I try to pick his brains. But he says it isn't his field.

Thursday:

Thumpy eyes, taut scalp, sensitised sinews, stiff neck . . . I am struck by the familiar symptoms of some nameless viruses, and midway through walking the dog I am too fatigued to continue. I call the Grove clinic on the mobile. Although things are running smoothly there, and I am kept waiting barely 10 minutes, by the time the receptionist asks me what the problem is, I have forgotten why I rang in the first place.

Friday:

The virus worsens, and I lie beneath a blanket on the sofa, doing what Rebecca calls my "Elizabeth Barrett Browning wan consumptive number". Yet for all the sharpness of her tongue, my wife is astoundingly attentive. She calls 11 times from her office for a bulletin - each time, perplexingly, on my mobile. When it rings for a 12th time shortly after noon, it is my physician, Sarah Jarvis. "Ah, doctor, thanks for calling back," I say, but she replies that I never called in the first place. The doctor chats away for ages before muttering something about wanting to contact someone called Penny but ringing the wrong number - and when I ask if she knows where I might come by a second-hand geiger counter, she hurriedly takes her leave.

Saturday:

A friend who keeps me in touch with cybermedicine emails recom mending an "ask the doctor" feature at AmericasDoctor.com. Although baffled by the home page, I manage to register to be kept up to date with major cancer and cardiac developments. Or so I think. Two hours later, a confirmatory email arrives, thanking me for volunteering and asking me to "ensure you arrive at the University of Wisconsin medical centre promptly by 9.30am on January 27, when the female stress incontinence clinical trial will begin."

Sunday:

Awake feeling dazed and distressed having passed a troubled night. In the dream, my Ericsson T28 goes missing and Rebecca promises to replace it. "Let's go and get the new one now, for your Christmas present," she says. The next I know, we are landing on the Sellafield helipad, where a white-coated Dr Jarvis greets us. "Hurry," she yells over the whirring of blades, "they've only got one Depleted Uranium phone, with WAP and text messaging, left in the shop." Hurriedly, Rebecca pays for the phone. When, within moments of calling the speaking clock, I notice a third eye in the middle of my forehead, I awake.

Monday:

Another troubled night, then a fretful day. Something is plaguing me, and has been for some time, but not until night do I work out what. "Of course, it's that nice professor," I yelp over the Indian takeaway. Rebecca eyes a forkful of Bombay aloo quizzically and asks me to expand. "The professor who asked us to his party . . . don't you think it's odd?" "Why?" "No one ever asks us to a party. Obviously someone's asked him to lure me over so he can examine me. It's a brain tumour, isn't it?" Rebecca snaps a poppadom in two."Remind me," she says, "what exactly he's a professor of?" "I told you before," I snap back, "gynaecology." Finishing her chicken korma, she replaces her cutlery and leaves the room.