In
Gary, Indiana,
U.S. postal inspector Harry Gruber is murdered by two men, Joe Regas and George Soderquist. They dump the body in
La Porte during a rainstorm, but when a nun named Sister Augustine walks past, Soderquist tries to distract her by helping to unfurl her umbrella and tells her that Gruber is drunk. Sister Augustine reports the incident to a nearby policeman. Postal inspector Al Goddard is assigned to the case. He traces Sister Augustine to a convent in
Fort Wayne and convinces her to cooperate with the investigation, and she identifies Soderquist from a
mug book. Goddard arranges for her to stay at a convent in Gary, hoping that she might identify Soderquist there in person. Goddard spots Soderquist with another gang member, Paul Ferrar, but Soderquist escapes. Regas, whom Sister Augustine does not recognize, sees her and telephones Earl Boettiger, the head of the gang and owner of the hotel where Gruber was killed, warning him to hide Soderquist. Later, when Soderquist refuses an order to leave town, they kill him. Goddard reasons that because Soderquist has not left town, the gang must still be planning something. The Gary postmaster suggests a likely target for theft: a money shipment that arrives regularly by train but must change to another train, involving a seven-minute truck ride between stations. Gruber had asked him about the truck's drivers, one of whom is Farrar, who Goddard recognizes. Goddard, posing as a corrupt inspector, pressures Ferrar to allow him to meet the head of the gang. He asks Earl Boettiger to join the gang, promising to be a more reliable inside man than is Ferrar. The plan is to steal the money shipment, expected to be worth $1 million. Regas is still worried about Sister Augustine and unsuccessfully tries to stage a fatal accident on the convent grounds. When Boettiger makes a last-minute change to the plan, Goddard has no choice but to phone the police from the gang's hotel. He is heard by Boettiger's mistress, hotel employee Dodie, but she protects him because she does not want to become an accessory to his murder and leaves town. When the robbery begins, Regas neglects his part in the preparations to take Sister Augustine prisoner, and when the gang meets, she blurts Goddard's name, revealing his deception. He pleads for her life and buys time by starting a fight. As police arrive, a shootout ensues in an industrial district, ending in the death of all the gang members. ==Cast==