(Warning: This post contains spoilers for the series finale of "Prodigal Son.") "Prodigal Son" ended its two-season run on Fox Tuesday night with a very abrupt series finale that the team behind the psychological drama intended only as a season finale. Unfortunately, the show was canceled by its broadcast home just two weeks before tonight's second-season closer, titled "The Last Weekend," leaving "Prodigal Son" with a gut-wrenching cliffhanger.