In Denver, almost $1 million is stolen when three thieves tunnel into a bank vault from an empty building next door that they've rented. Erskine and Colby lead the FBI's investigation. The ringleader, who spent all of an inheritance, plotted the crime so he could win back the woman he loves. The weaknesses of the three conspirators will eventually provide the clues the FBI men need to solve the case.
—Bill Koenig