The Peripatetic Piotti
In Gambit, Piotti's restaurant is located on 13th Street, east of Second Avenue (of course, in Manhattan). In "Poison à la Carte", published two years earlier, the restaurant is on 14th Street, between Second and Third Avenues, thus west of Second Avenue. Stout was not known for consistency in minor plot matters.
Read more about this topic: Gambit (novel)