Tod and Buz have been working on a tour boat on the Cuyahoga River in Cleveland, Ohio, for two months now. It is a job which Buz does not much like anymore due to the monotony of doing the exact same tour ten times a day, every day. They get a little excitement on the job when on one of the tours, a boy falls overboard, he who they are able to save. They learn he is eleven year old Richie McIntyre, the son of wealthy local businessman, Willard McIntyre. The story becomes more complicated when Richie claims that he was pushed overboard, a claim that the police have no reason not to believe as Mr. McIntyre received an anonymous note stating that what happened to Richie was no accident, and could happen again with more dire consequences. Tod and Buz and their boss, Captain Asa Turnbull get involved in the situation more deeply when they get caught in-between Mr. McIntyre, Richie and the note writer, the complete story which may only come to light when and if the note writer makes him/herself known.
—Huggo