Col. Brendon, Chief of the English Diplomatic office, upon his departure for France, turns the office over to Capt. Mills, with the understanding that Jim Clifford, one of the ablest men in the Secret Service, will assist him. Among the papers left in Capt. Mills’ care is a valuable document marked “File 117.” Capt. Mills invites the boys of the war office to his apartment to play cards. Jim goes but does not play. He amazes them by explaining that he possesses the almost uncanny ability to tell the value of his opponents’ hand. Capt. Mills loses heavily. In a rage he accuses Jim of being a sharp, and that he has been assisting one of the players by coaching him from behind. Jim resents this, and in a quarrel that follows Capt. Mills throws a glass of whiskey in his face. Later, his friends convince the Captain that he was in the wrong and owes Jim an apology. The Captain apologizes, but decides to give him an impossible task to perform and thus discredit him. Capt. Mills goes to the war office that night and abstracts “File 117” and the next day instructs Jim to search for it. At the end of a week he rebukes Jim for his unsuccessful search. Capt. Mills and Jim are invited by Lady Marion to spend the weekend at her place in the country. Capt. Mills accepts the invitation, but Jim remains behind to continue his search. He meets a cabman who asks him to return a cigarette case the Captain left in his cab a week before. Jim questions the cabman and learns that the Captain went to the war office after the card game in his home. Jim breaks into Capt. Mills’ apartment, and after drugging the butler searches the premises. He fails to find the missing paper. Jim then learns that Capt. Mills is going with the weekend party for a short cruise in the beautiful Grace Weston’s yacht. He disguises himself and succeeds in getting aboard. The next day the yacht tears a great hole in her side, when she crashes into treacherous drift ice. The entire party and crew, excepting Grace and Jim, get away in the lifeboats and are picked up by a steamer and taken back to England. Jim picks Miss Weston out of the water, in an unconscious condition, and takes her aboard a life raft. They land on an island along the coast. When they become hungry Jim suggests that he try to catch some fish, and asks his companion if she can spare anything from her apparel to use for a fishing line. While unlacing a string from her corset, she accidentally drops the missing papers from her bodice, which Mills had given her to keep for him. She recovers the papers quickly, but Jim decides to get them. The next day Jim and Grace are rescued, and taken back to England. In the meantime Col. Brendon has heard of the missing file, and calls Capt. Mills to task. The Captain, thinking the papers are lost with Grace, and knowing that Jim is mysteriously missing, places the blame upon him. Jim arrives, tells the Colonel of his experience, and is promptly promoted. Capt. Mills is dismissed from the service, and Grace, learning the truth of matters, finds that she has a growing interest in Jim.