Peter Blackstone, a Denver Private Investigator, is visited by Walter Endicott, a local car dealer, and his wife. They tell him about their son, Jonathan, running off with an older woman. It isn't until Peter finds out Walter tried to buy the woman off that Peter gets interested. Peter starts to investigate. With each turn, he finds someone new is involved in Jonathan's disappearance. It becomes obvious Jonathon Endicott was kidnapped and is being used as a pawn to extort money from Walter. Peter rents a place in Dillon after he finds out the woman may live in Frisco, Colorado. As he searches for the woman, he discovers that Jonathan might be on board a sailboat called the Crystal Blue on Dillon Reservoir, a large lake west of Denver. Peter decides to find out with the hope of getting Jonathan away from those holding him hostage. He also finds that it is not a simple case of extortion, but that it goes much deeper than that. Murder on the Crystal Blue is another Peter Blackstone Mystery novel.