The pair were serious about doing the books well, and for Eloise in Paris, they took two research trips to Paris to gather material for the book. When Simon & Schuster refused to pay for the second trip, Thompson got round-trip tickets from a Belgian airline in exchange for an appearance in the book. Thus, Sabena Airlines appears on three pages of Eloise in Paris. The concept for Eloise in Moscow was originally Eloise in England, but Thompson loved the idea of the wealthy little girl running around a socialist republic like the Soviet Union. To further the point, Knight hid a little man in a trenchcoat on every page of Eloise in Moscow. Pull out your old copy and see if you can spot them!
Thompson’s flamboyant personality, while charming, also meant she could be quite mercurial. She and Knight were working on a fifth book, Eloise Takes a Bawth, when Thompson abruptly halted publication and fired Knight for reasons unknown. The book was published posthumously in 2002.
Thompson continued to be unfailingly herself into her old age, allegedly subsisting solely on Coca-Cola in her later years. She lived with Liza Minelli until she passed away in 1998 at the age of 88.