Man, interrupted: in July of 1988, the life of 44-year-old ex-CFL star Terry Evanshen took such an extraordinary turn that it would come to resemble an ancient myth, a legend of the gods’ rough intervention in human affairs. The Man Who Lost Himself tells the story of a man – husband, father, decent Joe – who drives off in his car one day and never comes back. Thrown from behind the wheel in a traffic accident, Evanshen suffers such catastrophic brain injuries that his entire existence becomes a sort of hospital-bed labyrinth, a maze of science, death, and chance. Eventually a very different Terry Evanshen is returned to life: a composite being of faulty circuitry, puzzling instincts, and human soul – a postmodern Minotaur.

Callwood skilfully recounts the horrifying loss of so many elements of everyday humanity: short-term and long-term memory, physical agility, empathy, humour, sense of place, warmth, smell, even common sense. Evanshen’s family went through unimaginable grief and hardship as the man they knew was replaced by a disoriented, irascible, cold, and obsessive homunculus. But by the book’s end the man who had to build himself anew has wrestled some bricks of humanity into place.

Unlike the neurologist Oliver Sacks, who writes about similar assaults on human identity with a kind of limpid, poetic abstraction, Callwood’s approach is factual, even brisk. She’s a journalist, not an essayist; implicit in this book is the conviction that the human poetry and drama embedded in Evanshen’s odyssey speaks for itself, without the need for high-flown speculative embellishments. Such a policy can make excellent sense for the writer but can create an unrelieved horror show for the reader. There’s no breathing space, no nuanced frame for such a dark canvas, just page after grim page of every kind of pain and sorrow – even the dog dies. The narrative climbs to a hard-won summit (Evanshen’s fighting spirit is unquestionably a thing of awe), but by journey’s end some readers will feel flattened, not exhilarated.