"Bazaar of the Bizarre" is a sword and sorcery novelette by American writer Fritz Leiber and part of the canon of stories chronicling Fafhrd and the Gray Mouser.
One night in Lankhmar, the wizards Ningauble of the Seven Eyes and Sheelba of the Eyeless Face join forces and summon Fafhrd and the Gray Mouser to carry out a mission.
They are required to enter the Plaza of Dark Delights and obliterate an illegal bazaar established there by the Devourers, alien merchants who magically mesmerize customers into buying high priced merchandise which is actually worthless junk.
Fafhrd, aided only by the Blindfold of True Seeing and Cloak of Invisibility, given to him by the wizards, must perform the mission alone.
He manages to escape and rescue Mouser, who is still mesmerized into believing that the junk he sees is actually valuable, including books of ancient spells.