Fancy Dress! is a magazine story published in 1998.
One afternoon at Wellsworth, Gordon sees a lady wearing a nurse's uniform. He cheekily remarks that the lady is going to a fancy dress party, but he is told the lady is Nurse O'Neill, a real nurse. But Gordon was right; she is heading to a fancy dress party, but not in her work uniform. Nurse O'Neill is in a hurry and on her way to the station's exit, she trips over the baggage trolley. The nurse is helped up and she worries that her wrist may be sprained. The Fat Controller hears the commotion and orders the nurse to return to the hospital to be checked over. As the Fat Controller puts on a sling, the nurse tells him she still has not decided what to wear to the nurses' fancy dress party. The Fat Controller tells her to calm down, he cannot have "wounded soldiers rushing around the station". Gordon whistles and tells them that Nurse O'Neill could go to the party as a wounded soldier. The nurse likes that idea, she could borrow her father's army uniform. The Fat Controller helps the nurse aboard Gordon's train.
At the hospital, the nurse is treated for her sprained wrist and her father arrives with his old uniform. Back at Wellsworth, Gordon is very pleased with Nurse O'Neill's costume. The nurse then introduces Gordon to her father before she boards the train heading for the fancy dress party.
- On the front cover of the magazine, Nurse O'Neill has brown hair, but in the story her hair is blonde.