Connie Blair attends a convention in Atlantic City. While enjoying the winter sunshine in the hotel's solarium Connie meets David Maxwell,
who claims that he's there recovering from a tropical illness. That evening Connie dines with Hank Branson, the advertising manager of Standard Fixture in the dining room. She notices David staring at Abigail Whitney, an elderly guest who owns a poodle named Frosti. Abigail is dining with Emily Sloane, a dowdy looking woman who carries a wooden walking stick. Connie leaves the dining room and sees Abigail has left behind her purse. She decides to return it and when she reaches Abigail's room she finds that the door is ajar. Connie enters the room to return the purse and is strangled. Later, the public stenographer, Phoebe Miller, finds her unconscious in Abigail Whitney’s room.

Almost no one seems to believe Connie's explanation of why she was found in Abigail's room, the situation worsens when Abigail's valuable brooch is reported missing; Connie is believed to be the thief. Later, she learns that Abigail has dropped the theft charges. Abigail tells Connie that jewelry has been disappearing from her room. Connie spies on David when he visits a pawnshop, but she's unable to find out from the owner what he pawned.

One night she notices someone in the hotel's closed off wing so she and the house detective, Mr. Jones search the wing but they only find a spool of thread. A few days later, Connie takes Frosti with her and searches the deserted addition. She discovers Abigail's stolen jewels, which have been secreted away in one of the hotel's closed up rooms. Unfortunately, she is attacked again despite Frosti's presence. While recuperating in her hotel room, Connie uses Frosti to set up her attacker and solve the mystery of Abigail Whitney's stolen jewels.