Autumn 1908 finds Caroline Fremont Jones and her partner in love and work, Michael Kossoff, traveling incognito, riding the rails from San Francisco to Boston. The railroad hired the sleuthing couple to investigate a series of accidents. But before they can solve the mystery, they become victims of the worst mishap yet when their train blows up near Salt Lake City. Was it a callous act of vandalism-or something even more sinister? Michael isn't about to let his injuries slow down his search for answers...or for Fremont, who has not been seen since the accident-dead or alive.

Fortunately, the badly injured Fremont was rescued from the train's wreckage. But her unlikely savior, the leader of a breakaway Mormon sect, has hidden her away in his remote wilderness community. It seems that Melancthon Pratt has big plans for Fremont...not the least of which is for her to become his sixth wife. Now Fremont's only hope is that her genius for artifice will help her devise an escape. That is, unless Michael, shadowed by an old nemesis and a mysterious stranger, can find her before a heartless killer claims both their lives.