[1][2] When Iranian con-man Darius Koshay lands on the planet Vishnu, customs agent Luther Beck, who has tangled with him before, does everything he can to find an excuse to detain him before he can cause more trouble.

Koshay's ostensible object is to make and sell crackers to the planet's aborigines, of which he learned they were fond on a previous visit.

Vishnu is host to two intelligent native species, the six-limbed, apelike Romeli and the centaurlike Dzlieri, who are mutually antagonistic.

The planet Vishnu is a tropical world occupying the same star system as Krishna, de Camp's primary setting for the Viagens Interplanetarias series.

As dated in The Continent Makers and Other Tales of the Viagens and the 1959 version of de Camp's essay "The Krishna Stories", the action of "The Animal-Cracker Plot" takes place in the year 2120 CE.