Just before Christmas, department store clerk Steve Mason (Robert Mitchum) meets big-spending customer Connie Ennis (Janet Leigh) who is really a commercial spy. Steve unmasks her duplicity but when he discovers that Connie is a war widow he feels sorry for her and with the spirit of Christmas in the air and goodwill to all people, Steve decides to let Connie go. But his kind-hearted decision rebounds when the company fires him before the Christmas holiday. When Steve and Connie end up on a chance date, Connie's steady (Wendell Corey) is not impressed but her son Timmy (Gordon Gebert) is delighted. With her wedding booked for New Years day, can Connie choose between the safe yet dull Carl, or the handsome but unpredictable Steve Mason?