The memory of learning bad news tends to crystallise into distinct moments.
Christopher Hitchens was promoting a new book in New York, scheduled to appear on Jon Stewart's Daily Show that evening, when his heart began to beat strangely and he found that he could barely breathe.
The emergency services arrived and, he writes: "I had the time to wonder why they needed so many boots and helmets and so much heavy backup equipment."
In retrospect, "I see it as a very gentle and firm deportation, taking me from the country of the well across the stark frontier that marks off the land of malady."
He still made it to The Daily Show set and to a speaking engagement with his friend Salman Rushdie even later that evening. Soon afterwards, he discovered that he was dying.
Mortality is not an uplifting title and this can hardly be described as an uplifting book.
Hitchens, who succumbed to pneumonia as a complication of oesophageal cancer in December 2011, chronicled his illness in a column in Vanity Fair, where most of these essays first appeared.
They are vivid expressions of his engagement with death, looming from that opening paragraph where "some kind of shadow was throwing itself across the negatives".
By the book's end, the author has already departed and the afterword is written by his wife, Carol Blue.
Despite his struggle, through those final months Hitchens examined and interrogated cancer with characteristic doggedness.
This was his "year of living dyingly". He makes his illness work as a metaphor, a vehicle for meditations on war, language, philosophy and politics, infused (if you'll excuse the pun) with a deadly wit and humour.
He notes that he is not fighting cancer - it is fighting him. But in this assertively titled set of essays, he throws a tiny spear back in death's direction.
Some of what you can learn about cancer in this book is simply frightening.
The details Hitchens is willing to share about the treatments he received at America's most sophisticated hospitals are not for the faint of heart.
Towards the end, he was subject to cold feet, literally - "peripheral neuropathy" which he says describe the death-in-life of a system.
Yet there is a beauty in Hitchens' sheer ability to capture his experience. In these worst of circumstances, and maybe even inspired by them, he was a consummate writer and offered readers a prose limpid and pure.
His ability to write was threatened soon afterwards, when an injection to reduce pain in his arms, hands and fingers brought on a numbness in his extremities.
Hitchens had plenty of detractors - not only the Christian fundamentalists who saw cancer as a divine judgement on his atheistic views, but also many who found objectionable his statements about women, abortion, his support of the Iraq war and general contempt for the American left.
He was a divisive figure, who will be remembered both for his combative charm and for his literary brilliance.
Repeatedly in Mortality he cites the temptation to be self-centred, to feel self-pity; but he doesn't ever succumb. By turns shocking, intimate and astute, Mortality is a memoir like no other - as he must have wished it to be.