Who knows how many books would or will never have been written if Stephen King hadn't captured the melancholy flashback to boyhood with, first, "The Body," and then "Joyland"? A lot. That would probably include "The Chalk Man," the debut thriller by British author C.J. Tudor. By turns disturbing, sad, beautiful, creepy and wistful, "The Chalk Man" is a past-and-present story emceed by Eddie, a high school English teacher, that centers around the long-ago murder and dismemberment of a classmate. The incident touched Eddie and his group of pals in a huge way and hideously appropriated their own secret language — chalked-on sidewalks outside one another's homes as a call to action and adventure. By adulthood, the boys have grown mostly apart, and life's disappointments outnumber successes and expectations. But a sudden reappearance of the Chalk Man rekindles the past's long-buried and unsolved nightmares. Beautifully done and full of thoughtful, eerie plot spins.