While interviewing Kasso, newly-appointed ambassador to the United States, reporter Roy Burton meets Kasso's daughter Vera and the two fall in love at first sight. Paul and his assistant Michael, a butler in Kasso's household, are plotting the ambassador's death. Roy gets on their track by Russian conspirators headed by Alexis and promises Vera to do all in his power to run down the conspirators. He follows Paul to their hiding place, but is followed by Michael, knocked senseless, and dragged into their lair. Alexis prevents him from being killed at once, saying he has a better plan to make use of Roy. He succeeds in making Roy a hypnosis subject, perfects a concussion bomb, and plans to have the hypnotized Roy hurl it at Kasso. Vera recognizes Paul on a streetcar and follows him to the den, but as she is looking through the door, he springs out and overpowers her. He drags her inside and is left in charge of her while Alexis and Michael take Roy to Kasso's house. Paul endeavors to make advances to Vera, but she manages to fell him with a bottle, then finding the door locked, blows it open with one of the conspirator's bombs, and with two policemen, dashes to her father's house. Alexis, using his hypnotic power, forces Roy to walk up to Kasso, holding the deadly bomb behind him. Just as he raises it to hurl it at their feet, Vera rushes up and seizes his arm, while the conspirators are made prisoners. Alexis boasts that no one can break the hypnotic spell he has cast over Roy, but Vera's love proves stronger, and Roy is freed from its sway.