After researching the legend of the treasure of Langley Towers, Sir Owen Langley informs his daughter Pauline that he has discovered the hidden meaning of the doggerel verse left behind by an ancestor as a clue to its hiding place. But then he mysteriously disappears, after rushing out of the house in the middle of the night in his pyjamas! On the same night, the legendary figure of the Black Hunchback - the sinister family spectre that haunts the Towers and heralds death - is spotted by Pauline on the lawn...