It takes place in Smith's Instrumentality of Mankind universe, and was heavily influenced by the classic Chinese novel Journey to the West.

To safeguard their archaic way of life (resembling Australian ranchers with a British cultural inheritance), the Norstrilians are forced to develop the most advanced defense force and weaponry known (for example, Mother Hitton's Littul Kittons); to protect their culture, imports from other worlds are taxed at rates exceeding 20 million percent, reducing what would be a staggering fortune on another planet to humble penury on Norstrilia itself.

After his last test—which he finally passes with the aid of a Lord of the Instrumentality and his own freak telepathic talents—he learns that an envious former friend, who suffers from an allergy to stroon and so is condemned to live a mere 150 years or so, seeks to kill him, using the pretext that the test was biased and administered unfairly.

To escape the danger, he amasses an immense fortune overnight by playing the futures market in stroon, following a plan formulated by his ancient computer (which has certain more-or-less illegal quasi-military capabilities) which was passed down to him by an eccentric ancestor.

After a series of adventures among the "underpeople" (animals genetically modified to resemble humans and possessing intellects that sometimes surpass their masters', used as slaves and generally despised) in the company of the bewitching Cat-woman C'mell, he meets their leader, E'Telekeli, an experimental creature of bird origin with enormous psychic powers.

The second half was also published in shorter form in 1964, in Galaxy's sister magazine If as "The Store of Heart's Desire", before seeing posthumous publication as The Underpeople in 1968.