Big Anthony Tagliabue is a local character whose fiancée Agnes Ann owns a stable on the eponymous offshore island. She is secretly training a promising filly for the track when she discovers that Tagliabue also harbors a secret: he’s a deep-cover operative who is called to duty when a Russian spy ship transits the coast on her way back to St. Petersburg.

Giselle, Tagliabue’s enigmatic and exotic handler, intimates that his mission to rescue a defector from the Leonov might also ameliorate his thirst to find the killers of his mate. Agnes Ann is not so sure about Giselle. The result is a tense tale of high-seas adventure off Georges Bank, racing drama at Saratoga, bloodletting in the north woods, and intrigue on Westfarrow Island.