So Long at the Fair

Vicky Barton and her brother Johnny arrive in Paris to attend the Exposition Universelle. They check into the Hôtel de la Licorne and, after settling in, head out for dinner and a look at the famous Moulin Rouge. That first night, Johnny has a late-night drink while Vicky goes to bed.

George Hathaway asks Johnny for change for a 100-franc note to pay a carriage driver. Johnny lends him 50 francs and, pressed for repayment, provides George with his name and room number.

That morning Vicky discovers Johnny is missing and the wall of his adjacent room has disappeared, its former doorway now part of the common bathroom. The disappearance triggers panic and a frantic search as she tries to understand what happened.

Vicky questions Madame Hervé, the hotel owner, who insists Vicky must be mistaken about Johnny's stay. Narcisse and the day porter corroborate her story, casting doubt on Johnny's existence and complicating Vicky's quest for the truth.

Frantic, Vicky seeks help at the British consul, who can offer little proof of Johnny's presence and suggests finding a witness, Nina, the hotel maid. Nina had mentioned plans to go up in a balloon at the Exposition that day.

Nina's balloon ascent with her boyfriend goes tragically wrong; the balloon bursts into flames and crashes to the ground, killing the two passengers. The day’s spectacle becomes a grim reminder of the danger surrounding the hotel and its guests.

Vicky turns to the French police commissaire, who questions Madame Hervé and her brother but detects nothing amiss in their story. With no proof of Johnny's presence, the investigation stalls and Vicky's hope wanes.

Because Vicky's stay was booked for only two nights, Madame Hervé provides her with a ticket home to England. She must depart despite her desperate unresolved questions about Johnny and the hotel.

Rhoda O'Donovan, working with George, slips a letter containing George's repayment address under Vicky's door. Reading it gives Vicky a possible route to locating Johnny and reconnecting with George.

Vicky goes to see George, who confirms having met Johnny and offers his help. He studies the hotel exterior and notices there are six balconies on Vicky's floor, but only five rooms, hinting that a hidden room has been concealed behind the wall.

George's investigation leads to the discovery of the missing hotel room concealed behind a wall that had been boarded up to hide Johnny's whereabouts. The hidden space explains the earlier disappearance and the altered floor plan.

Under questioning, Madame Hervé reveals Johnny's fate: he fell ill on the first night and a doctor diagnosed bubonic plague. Fearful that news of a plague would ruin the Exposition, the hotel and doctor secretly remove him to a rundown hospital and conceal his existence.

George brings Doctor Hart to examine Johnny. The doctor tells Vicky there is a chance Johnny may live with proper treatment, providing a sliver of hope amid the chaos.

As clues unfold and Johnny's fate hangs in the balance, a romance grows between George and Vicky. They work together to uncover the truth and help save Johnny from the hospital's concealment.