She has often suspected that her last words to herself and in this world will prove to be 'You bloody old fool' or, perhaps, depending on the mood of the day or the time of the night, 'you fucking idiot'. As the speeding car hits the tree, or the unserviced boiler explodes, or the smoke and flames fill the hallway, or the grip on the high guttering gives way, those will be her last words. She isn't to know for sure that it will be so, but she suspects it. In her latter years, she's become deeply interested in the phrase 'Call no man happy until he is dead.' Or no woman, come to that. 'Call no woman happy until she is dead.' Fair enough, and the ancient world had known women as well as men who had met unfortunate ends: Clytemnestra, Dido, Hecuba, Antigone. Though of course Antigone, one must remember, had rejoiced to die young, and in a good (if to us pointless) cause, thereby avoiding all the inconveniences of old age.

Fran herself is already too old to die young, and too old to avoid bunions and arthritis, moles and blebs, weakening wrists, incipient but not yet treatable cataracts, and encroaching weariness. She can see that in time (and perhaps in not a very long time) all these annoyances will become so annoying that she will be willing to embark on one of those acts of reckless folly that will bring the whole thing to a rapid, perhaps a sensational ending. But would the rapid ending cancel out and negate the intermittent happiness of the earlier years, the long struggle towards some kind of maturity, the modest successes, the hard work? What would the balance sheet look like, at the last reckoning?

It was the obituaries of Stella Hartleap that set her thoughts in this actuarial direction, as she drove along the M1 towards Birmingham, at only three or four miles above the speed limit.

The print obituaries had been annoying, piously annoying, in a sexist, ageist, hypocritical, mealy-mouthed manner, reeking of Schadenfreude. And just now, yet another mention of Stella on the car radio, in that regular Radio 4 obituary slot, has revived her irritations. She hadn't known Stella very well, having met her late in the day in Highgate through Hamish, but she'd known her long enough to recognise the claptrap and the bullshit. So, Stella had died of smoke inhalation, having set her bedclothes on fire while smoking in bed in her remote farmstead in the Black Mountains, and having just polished off a tumbler of Famous Grouse. So what? A better exit than dying in a hospital corridor in a wheelchair while waiting for another dose of poisonous chemotherapy, which had recently been her good friend Birgit's dismal fate. At least Stella had nobody to blame but herself, and although the last minutes couldn't have been pleasant, neither had Birgit's. Not at all pleasant, by all accounts, and without any complementary frisson of autonomy.

Birgit wouldn't have approved of Stella Hartleap's end. She might even have been censorious about it. She had been a judgmental woman. But that was neither here nor there. We don't have to agree with anyone, ever.

Her new-old friend Teresa, who is grievously ill, wouldn't be censorious, as she is never censorious about anyone.

I am the captain of my fate, I am the master of my soul. A Roman, by a Roman, valiantly vanquished.

There is a truck, too close behind her, she can see its great dead smeared glass underwater eyes looming at her in her driving mirror. In the old days, Hamish used to slam on his brakes in situations like this, as a warning. She'd always thought that was dangerous, but he'd never come to any harm. He hadn't died at the wheel. He'd died of something more insidious, less violent, more cruelly protracted.

She chooses the accelerator. It's safer than the brake. Her first husband Claude had believed in the use of the accelerator, and she was with him on that.

Francesca Stubbs is on her way to a conference on sheltered housing for the elderly, a subject pertinent to her train of thought, but not in itself heroic. Fran is something of an expert in the field, and is employed by a charitable trust which devotes generous research funds to examining and improving the living arrangements of the ageing. She's always been interested in all forms of social housing, and this new job suits her well. She's intrigued by the way more and more people in England opt to live alone, in the early twenty-first century. Students don't seem to mind cohabitation, even like it, and cohabitation is forced upon the ill and the elderly, but more and more of the able-bodied in their mid-life choose to live alone. This is making demands on the housing stock which successive governments are unable and possibly unwilling even to try to satisfy.

Fran is in favour of a land tax. That would shake things up a bit. But the English are extraordinarily tenacious of land. They hate to relinquish even a yard of it. The word 'freehold' has a powerful resonance.

No, there is nothing heroic about the housing stock and planning policy, subjects which currently occupy her working life, but old age itself is a theme for heroism. It calls upon courage.

Fran had from an unsuitably early age been attracted by the heroic death, the famous last words, the tragic farewell. Her parents had on their shelves a copy of Brewer's Dictionary of Phrase and Fable, a book which, as a teenager, she would morbidly browse for hours. One of her favourite sections was 'Dying Sayings', with its fine mix of the pious, the complacent, the apocryphal, the bathetic and the defiant. Artists had fared well: Beethoven was alleged to have said 'I shall hear in heaven'; the erotic painter Etty had declared 'Wonderful! Wonderful this death!'; and Keats had died bravely, generously comforting his poor friend Severn.

Those about to be executed had clearly had time to prepare a fine last thought, and of these she favoured the romantic Walter Raleigh's 'It matters little how the head lies, so the heart be right'. Harriet Martineau, who had suffered much as a child from religion, as Fran had later discovered, had stoically remarked, 'I see no reason why the existence of Harriet Martineau should be perpetuated', an admirably composed sentiment which had caught the child Fran's attention long before she knew who Harriet Martineau was. But most of all she had liked the parting words of Siward the Dane who had commanded his men: 'Lift me up that I may die standing, not lying down like a cow'. She didn't know why this appealed to her so strongly, as she was herself very unlikely to die on a battlefield. Maybe it meant she had Danish blood? Well, she probably had, of course, as many, perhaps most of us in England have. Or maybe she had liked the mention of the cow, which she heard as strangely affectionate, not as contemptuous.

She was much more likely to die on a motorway than on a battlefield.

The Vikings hadn't approved of dying quietly and comfortably in bed. Unlike her first husband Claude, who was currently making himself as comfortable as he could.

She has pulled away from the truck, and is now overtaking a dirty maroon family saloon with an annoying sticker about its 'Baby on Board'. There is an anonymous dirty white van just behind...