Plot

A crippled young girl writes Superman a letter asking him to take her to the fair for her birthday, but before he arrives she is kidnapped by a group of counterfeiters who need information that she has been given by mistake.

Synopsis - The Birthday Letter Opening with Lois Lane reading the letter to Perry White from Kathy Williams asking for Superman to take her to the fair, explaining she is handicapped and cannot get around as easily as other kids. Kathy Williams answers her home phone, the caller leaves a message unintelligible to Kathy, assuming it was a wrong number. The caller, Herman Cusak, was passing on information to whom he thought was the correct receiving party, the Duval's. The number Cusak had was obviously wrong, someone wrote it down incorrectly, and he was killed in the phone booth making the call. Marcel Duval learns from the phone company the number Cusak called was the Williams home, coincidentally the number appears in the Daily Planet Slugger is reading where Kathy is requesting Superman take her to the fair, showing the paper to Marcel and Marie Duval. The matter of getting Superman to appear at Kathy's house can be solved by having Slugger stand in for Superman. Clark tells Lois Superman has not let you down in the past and I don't think he will let you down now. Superman flies to Kathy's house, finds out someone claiming to be Superman has been there per Kathy's note shown by her mother. The man dressed as Superman, Slugger, takes her out on the fire escape, then returns her to their couch, the Duval's claim to be the aunt and uncle, Kathy doesn't believe it. Kathy remembers part of the message Cusak gave, but not the location, but the crooks believe she will remember after her cake and ice cream. Birthday treats, presents and toys do not jog Kathy's memory, Slugger is left to entertain while the Duval's go to Kathy's to retrieve her doll, thinking the doll will jostle her memory. Perkins shows at Kent's office where he and Lois are frustrated over events unfolding; Perkins says the phone number Cusak called was written down on a piece of paper the couple took when they stopped by the shop. The description of the couple Perkins gives the reporters is enough for Clark to check with the FBI while Lois goes to Kathy's to assure her mother Superman is innocent and will help the police find Kathy. The Duval's are at Kathy's looking for her doll, Lois enters, explaining why she is there, saying she came a little early with no Mrs. Williams, she ducts out, hiding around the corner hallway, the Duvall's leave and Lois follows them. Lois gets caught in traffic, Duval's got free, but Lois confirms their identity with pictures from the FBI. Duval's hired a man named LaRue to steal plates for counterfeiting. LaRue double crossed them bringing the plates to America for sale on the black market. Cusak was calling to give the address where the plates could be obtained when he was gunned down in Perkin's shop. Duval's return, find Slugger carrying Kathy out, Slugger is tied to a chair, Kathy's leg brace is removed, Duval's departing for the location of the plates. It was Kathy's singing doll reminding her of the location where LaRue would have told Cusak. The cab driver calls Kent giving him the address of the Duval's destination leaving Perkin's shop. Clark requests Henderson meet them at the apartment. Henderson unties and arrests Slugger, Lois fits Kathy with her brace, Kathy tells the reporters and the police the Lambert Engraving Co. at 10 o'clock. Clark leaves saying he has to find Superman to catch LaRue and the Duval's. Duval's arrive at the engravers, they find LaRue, Duval says the plates were to be delivered two months ago in Paris, a gun fight ensues between Marcel and LaRue, Superman intervenes, knocks out LaRue, and subdues Marcel. Marie drops the plates in the acid bath, but Superman retrieves them asking they be returned to the Bank of France. Hanlan and henchmen are outside, arrested by Henderson, as is Marie Duval. Hanlan was to buy the plates from LaRue. Superman takes Kathy to the fair.