The Chain of Chance

In this way, the natural laws of probability and chaos theory play the role of suspects and characters in a murder mystery, lending elements of science fiction to the novel.

The underlying philosophical idea is expanded on by Lem in his major essay The Philosophy of Chance.

[1] A former astronaut is hired by a detective agency to help in an investigation of a case of mysterious deaths.

Several victims became mad and committed suicide during their vacation in various Naples spas, apparently without reason.

One of chemical compounds involved in the deadly mixture comes from an anti-allergic drug, which the hero takes for allergic rhinitis, hence the novel's original title.