Plot summary

When dogs and men suddenly disappear, and strange screams fill the night, fantastic stories of vengeful ghosts are almost believable. It is these strange happenings which bring Frank and Joe Hardy to the Pocono Mountains to help their father's friend, a retired police captain, solve the mystery of Black Hollow. But when the Hardy Boys and Chet Morton arrive at Captain Thomas Maguire's cabin on the edge of the hollow, he has disappeared. In the woods the boys find only a few slim clues: a flashlight bearing the initials T.M., a few scraps of bright plaid cloth, and two empty shotgun shells which had been fired recently. Frank and Joe are determined to find the captain, despite Chet's misgivings after a night of weird and terrifying screams. Neighbors of the missing man insist that the bloodcurdling cries are those of a legendary witch who stalks Black Hollow seeking vengeance. Strangely, it is a small puppy that helps the boys disclose a most unusual and surprising set of circumstances, involving a mute boy, an elusive hermit, and a fearless puma trainer.

• Publication date: 1962
• Ghostwriter: James Buechler
• Summary: In the Pocono Mountains, the boys search for their father's missing friend and solve the mystery of the purportedly haunted Black Hollow.