Based on a referral from acquaintance Gus Papitos who he has not seen in several years, former New York City cop turned Chicago based private investigator John Rosow, who likes his martinis a little too much even while on the job, is hired at the last minute over the telephone by attorney Drexler Hewitt, a man he's never met, to follow a middle aged male subject on the soon departing California Zephyr train to Los Angeles.
Hewitt only providing a photograph, Rosow has no idea who the subject is or why Hewitt wants him followed. Beyond the initial telephone call by Hewitt himself, Rosow is to contact his associate, Miss Charley, with any issue about the job.
It isn't until he boards the train that Rosow believes that the Hispanic adolescent boy accompanying the subject may be of equal or even the true person of interest for Hewitt. As Rosow tails the subject and the boy from Chicago to Los Angeles and throughout Southern California, he encounters some odd characters along the way, some who he will learn he did not meet by accident.
But also along the way, Rosow begins to learn more about the subject. When Rosow finally discovers the reason for this case, he has to decide whose interest is of utmost importance, all the players who seem to be working on their own self-interest incompatible with everyone else's.
Rosow's own history with an event of mutual interest may help him decide what to do.