Hardy Boys 11 - While the Clock Ticked

Frank and Joe solve the mystery of the secret locked room in the spooky Dalrymple Mansion.
A banker named Ray Dalrymple of Lakeside gets death threats and shows up at the Hardy's house seeking Fenton Hardy's assistance. Frank & Joe offer to help, but at first he's reluctant. At last, he agrees. Soon after that, during a hike with their friends, the Hardy boys are nearly run over by a car, then investigate the Purdy place. After that, they rest and talk over their recent mis-adventures.