The River King features police officer Abel Grey (Edward Burns), struggling to get to the truth about a student's death while he tries to cope with flashbacks about his brother Frank's suicide years earlier. The body of Gus Pierce (Thomas Gibson) is found under the ice of the River King, and Carlin Leander (Rachelle LeFevre), Gus's only friend, tells Abel that Gus was being bullied. This leads Abel to investigate Gus's death, but the Dean (Ross Petty) of the exclusive Haddan School tells police that Gus committed suicide, heading off any possible scandal involving bullying and hazing. Abel secretly asks for help from Betsy Chase (Jennifer Ehle), a teacher at the school, and as he digs deeper, the Police Chief (Richard Fitzpatrick) pressures him to drop the investigation. Abel is determined to get to the truth on several levels, hoping that by honoring Gus's life, he can also come to terms with his role in his brother's death.