Myth-ing Persons / Little Myth Marker

Skeeve, a powerful young magician, and his companions venture into an upside-down dimension to search for his missing demon partner, Aahz, in Myth-ing Persons, and finds himself saddled with Markie, a pint-sized troublemaker, as an IOU for a high-stakes poker game in Little Myth Marker, in an entertaining omnibus volume. Reprint.