The book seems to argue in favor of the idea that social conditions rather than heredity shape a person's character and behavior (the nature versus nurture debate).

As depicted again and again in the course of the book, people born with precisely the same genetic heritage can - given different social conditions - develop completely different character traits (timid or assertive, benevolent or predatory, etc.)

Used as a pawn by Christophe's con-man boyfriend Larry Douglas to entrap a left-wing activist and former actor (who turns out to be Ronald Reagan), he is later detained and brought to New Mexico to unravel a mystery.

The focus then shifts to another Dominic DeSota, a United States Senator having an affair with Nyla Christophe Bowquist, who in this world is a famous violinist.

DeSota brings the entire group back to his universe—Paratime Alpha—where he explains that since the senator's escape that Paratime Gamma has invaded the Epsilon's Washington DC in a failed bid to capture the president.

There, they are informed that they have been transported by a group of more advanced alternate Earths to stop ballistic recoil before it escalates and the barriers between universes become irreparably permeable.

Dave Langford reviewed The Coming of the Quantum Cats for White Dwarf #89, and stated that "Pohl, a reliably thoughtful author, goes one better than his semi-happy finale.