When her sculptor-uncle dies, Jill Spencer arrives with her sister Carol at his house, eager to search for the fortune which Uncle Leon had mentioned. They step from their car and Jill sees a suspicious form dart across the lawn; thus a mood of suspense is set. There's some dating and a square dance to fill in time, plus visits from Leon's lawyer and Mr. Krush, a neighboring sculptor, who both want to buy the house. Jill comes close to death -- she's tied and gagged -- but when Mr. Krush (who turns out to be the scoundrel) returns to finish her off, she has already been freed by a young boy-friend. Before discovering Leon's fortune, some valuable statues hidden in a strange subterranean vault are uncovered. Mechanical mystery, constructed on hollow ground.