Books like The Witchmaster's Key by Franklin W. Dixon

When Mr. Hardy from the West Coast calls Frank and Joe, they are thrust into a thrilling overseas investigation. Their trip to England to aid Professor Rowbotham begins with a strange omen: the bizarre funeral of an old witchmaster. Over the next few days, the twins find themselves shadowed, trapped, and pursued by a massive black dog, all as a sinister curse from an old crone takes hold. The mystery deepens when they discover that the burglars who stole invaluable artifacts from the professor’s witch museum are linked to the disappearance of Lord Craighead. Dangerous encounters carry the Hardys from the English countryside to Ireland and the Isle of Man. Even a shipwreck in the storm‑tossed Irish Sea cannot stop them—until a frightened white witch leads them into a black witches’ coven’s torture chamber. In a final confrontation with fanatic adversaries, Frank and Joe barely escape alive, snatching the coveted Witchmaster’s Key.

First publish date: 1976