India, Oct. 3 -- At 85, Jeffrey Archer says he is writing his last novel.

His latest is End Game, the eighth and last book in the William Warwick crime thriller series. It was released on September 23.

"The one after this will be bigger than Kane and Abel," Archer says (referring to his 1979 bestseller, one of the titles for which he is best-known). "I wrote a 100-page outline for it six years ago, but I wanted to take my time and finish the Warwick series first."

What happens after it is done? "I will be writing. short stories, plays and screenplays. You can't take stories out of me. It's what I do best," he says.

That's good news for fans who have followed his work for nearly half a century, ever since his first novel, the economic-...