 As of 2018 this is the last Hardy Boys story to be published by Grosset & Dunlap

Chet Morton's cousin, Vern, is on his way to California to find a rare and valuable coin mysteriously missing from his uncle's bank vault.When he stops in Bayport, his brand-new car is stolen.The Hardys take on a double mystery – and double danger – as they head for the West Coast to investigate this sinister mystery.