The story is told in the first person, and the nameless detective known only as The Continental Op investigates a theft of diamonds from the Leggett family of San Francisco.

The plot involves a supposed curse on the Dain family, said to inflict sudden and violent deaths upon those in their vicinity.

The Continental Op, on behalf of four successive clients, investigates the reason behind all the mysterious, violent events surrounding Gabrielle Leggett, which he eventually uncovers.

The concluding chapters of the novel contain a detailed description of how the Op weans her from her drug habit, and the novel ends on a hopeful note.

Swackhamer and producer Martin Poll, which starred James Coburn (as the Op, given the name "Hamilton Nash" for this film version), Hector Elizondo (as Ben Feeney), Jean Simmons (as Aaronia Haldorn), Jason Miller (as Owen Fitzstephan), Beatrice Straight (as Alice Leggett), Paul Stewart (as the Old Man), Nancy Addison (as Gabrielle Leggett), Tom Bower (as Sergeant O'Gar), David Canary (as Jack Santos), Beeson Carroll (as Marshall Cotton), Roland Winters (as Hubert Collinson) and a pre-Star Trek Brent Spiner (as Tom Fink).