“ ‘Universe’ doesn’t seem ample enough, because each book shows you how much bigger his world is and expands the limits of what we think his stories are,” said David Ebershoff, Mr. Mitchell’s editor at Random House. “His new novel is really the first time that many readers can begin to piece the books together.”

“The Bone Clocks,” which is being released on Sept. 2, is Mr. Mitchell’s most ambitious work yet, and provides the key to a larger narrative puzzle — a kind of rambling macronovel — that he has been assembling across his books. Characters from his earlier books appear in major roles that cast their previous literary incarnations in a strange new light. Themes and motifs that echo across his books — survival, mortality, the perils of power and the possibility of rebirth — are amplified and refined.

“In the same way that my novels are built of hyperlinked novellas, I’m sort of building what I’ve taken to calling in a highfalutin way the ‘uberbook’ out of hyperlinked novels, because I’m a megalomaniac, and I like the idea of maximum scale,” Mr. Mitchell said.

“The Bone Clocks” opens in 1984 England, where a rebellious teenager, Holly Sykes, runs away from home and unwittingly gets caught up in an occult war that has been raging for centuries. In classic Mitchell fashion, the narrative transgresses time, space and genre, jumping from 1980s England to contemporary Iraq, the medieval Swiss Alps, the 19th-century Australian outback, a Manhattan townhouse that serves as a metaphysical portal, and finally to an Irish village in 2043, where an elderly Holly struggles to protect her grandchildren after an environmental catastrophe. As the story progresses, Holly learns that she has been a pawn in a battle between two rival camps of immortals, the Horologists, who reincarnate by taking on new bodies, and the Anchorites, who stay eternally young by preying on the living.

Image “The seed of the story was my impending midlife crisis and an exploration of what I’d be prepared to do to cheat aging and death,” Mr. Mitchell said. Credit... Eoin O'Conaill for The New York Times

Mr. Mitchell, 45, says “The Bone Clocks” grew out of a new preoccupation with mortality. “The seed of the story was my impending midlife crisis and an exploration of what I’d be prepared to do to cheat aging and death,” said Mr. Mitchell, who is English and lives in Ireland with his wife and two children.