In Agatha Christie's mystery Murder on the Orient Express, Mrs. Caroline Hubbard appears to be an extremely talkative American lady. In chapter 4, the narrator remarks that Poirot already knows all about Mrs. Hubbard's daughter and presumably Mrs. Hubbard herself, and that “Everyone on the train who could understand English did!” In other words, Mrs. Hubbard has a gift to gab, and she chats voraciously with anyone who will listen, willingly or not. She spreads her story far and wide, making sure that everyone knows that she has just been to visit her daughter in Turkey.

Mrs. Hubbard, however, is not at all who she seems to be. In fact, the woman's name is not even “Mrs. Hubbard.” She is in reality Linda Arden, a famous actress and the grandmother of the murdered little girl Daisy Armstrong. She is out for revenge against her granddaughter's murderer, who is a passenger on the Orient Express. As a talented actress, Linda Arden has no trouble playing the part of Mrs. Hubbard, even though the woman is nearly exactly the opposite of her own personality. Indeed, she hopes that as Mrs. Hubbard, she will appear so innocent and frivolous that no one will suspect her true identity or her murderous plot. Perhaps she would have retained the role of chatty, silly Mrs. Hubbard until the end if the famous detective Hercule Poirot had not also been a passenger on the Orient Express.