Foxhall Ridgeway, a bachelor from Vienna, Wyoming, checks into the swank Hotel Diplomat in New York, where he intends to find an eligible young lady to marry and take back to his ranch. Also checking into the hotel, in the room next to Foxhall's, is the unscrupulous stock trader Arthur Carlisle and his assistant Mr. Kent, in whose name the suite has been secretly registered. Soon after his arrival, Carlisle blackmails the lovely Countess Louise Broussiloff into meeting him in his room for a private rendezvous. Louise, who received money for her dress shop from the shiftless broker, is told by Carlisle to follow him up to his room unless she wants her fiancé, George Sheridan, to be told of her affair with him. Seeing no way out, Louise follows Carlisle upstairs, but not before instructing her friend Phoebe, a hotel phone operator, to tell anyone asking about her whereabouts, especially George, that she has not been seen in the hotel. When the desperate Foxhall uses the hotel phones to make three unsuccessful attempts to arrange dates with former flames, he receives a ribbing from the eavesdropping Phoebe, who is attracted to him. When Louise returns from Carlisle's room, she tries to tell Phoebe that her blackmailer is dead, but is prevented from doing so by George's arrival. While dining with George, Louise realizes that her bracelet is missing. She excuses herself to tell Phoebe of the murder and to ask her to retrieve the bracelet before she is suspected of committing the crime. When Foxhall discovers the body, he informs Collis, the hotel manager. Collis then meets Foxhall in Carlisle's room, and when they find the body missing, they question Kent, who denies having seen the corpse. Despite his best efforts to stay out of it, Foxhall becomes involved in the intrigue when Phoebe implores him to help her find the bracelet belonging to the countess. With plans to silence the meddling Foxhall, Collis and Kent conspire to keep the news of the powerful stock broker's death a secret until after the market opens, so that they can make a fortune by selling his stocks short and then buying them back cheap after the news is publicized. After searching for the bracelet with no success, Foxhall asks Louise what transpired in Carlisle's room, and she tells him about the broker's plans to take her to South America and how he attacked her when she refused. Louise also tells Foxhall that when she heard someone knocking at Carlisle's door, she hid herself, and when she returned she discovered his dead body. Believing his life to be in danger, Foxhall goes to his trunk to get his gun, but when he opens it, Carlisle's body, with Louise's bracelet in its pocket, falls out. At that instant, the lights go out and Foxhall is attacked. After Foxhall regains consciousness, he finds a black button that he tore off his attacker's coat during the scuffle, which he uses to identify Kent as the murderer. Having solved the mystery, Foxhall returns Louise's bracelet and then proposes to Phoebe, who consents to marry him and return to Wyoming with him.
