Private detective Nick Carter is summoned to Washington by his old friend Cortland Grand to meet Senator Monrose, who heads a committee investigating subversive groups in the U.S. Nick turns down the Senator's request to assist his committee, and asks Cortland to fly him back to New York that night aboard his personal plane. Joining Nick on the flight back to New York are six beautiful models accompanied by their chaperone, detective Christine Cross, and Andrew Hendon, a polo star suspected of being a spy. Upon landing, Hendon is discovered murdered, with a nail file belonging to Pat Evens, one of the models, lodged in his throat. As Nick questions Pat, three spies wait on the landing strip, intent on silencing Pat before she can talk. The three strangle the pilot, leaving the plane to careen dangerously until Nick grabs the controls. Once the plane is safe, Nick takes the passengers to Cortland's country house, where he begins to question Pat again. As Pat is about to tell her story, machine gun fire rattles the house, prompting Nick to dress his assistant, beekeeper Bartholomew, in Pat's robes to decoy the killers. Nick and Pat then escape in the sheriff's car but are apprehended for car theft and locked in jail, where the spies plant a bomb at their window. Escaping the explosion, Pat and Nick take refuge in Cortland's New York apartment. There, Pat tells Nick that the spies had been threatening to kill her father, whom they are holding captive in Europe, unless she agreed to work with Hendon. As Pat tells her story, Bartholomew and Chris trace the spies to their hideout behind a printer's shop, where they are taken prisoner. After sequestering Pat in a small hotel, Nick speaks with the Senator and realizes that Cortland has been withholding information and therefore is probably the leader of the group. Nick traces Bartholomew through his bees, and as he goes to rescue his assistant, Kathe, one of Cortland's spies, kidnaps Pat. After rescuing Bartholomew and Chris, Nick alerts the police ,who then arrest the spies and free Pat. Setting a trap for Cortland, Nick and the Senator board his plane, and after Nick tricks him into a confession, the power-mad Cortland dies in a shootout.