A compelling protagonist and a riveting premise search for a story, in a dark fantasy that reads like a Twilight Zone episode. Sixteen-year-old Cassie has always seen the “mark” around someone about to die, but has only recently realized its significance. After her beloved grandmother’s death, Cassie is forced to spend the summer with a distant aunt, grappling with the implications of her “gift.” She tumbles into a passionate affair with the handsome TA of her philosophy class, who has his own ideas about the responsibilities of such foreknowledge. Cassie is a thoughtful, sympathetic character whose struggles with her unpleasant power feel very real; her agonizing over confronting strangers with their imminent death is heartwrenching. The other characters, however, serve only to convey information and illustrate various ethical positions. As the coincidental revelations of long-concealed secrets pile up, the plot lurches into implausibility, with a conclusion frustratingly devoid of any resolution. Still, the ideas explored could inspire heated classroom debates, and philosophically inclined teens will find that the central question of “What happens now?” will linger long after the many plot holes are forgotten. (Horror. YA)