A man is seen falling from an apartment building, yet the corps found there is not his but Michael Johnson, a resident, who was deeply wounded by an unidentified round object. First subject is junkie Doug Ramsey, who is arrested by Horatio for probably abseiling to break in and steal the $100,000 heirloom ring of the condo owner, Edward Mathis, who is however found taking it back after its sale, insurance fraud. The wounding object is found, a CD recording kinky sex scenes of missing Donna Scott and reputedly strict criminal judge Isaac Greenhill, whose former court clerk is Mathis, who apparently blackmails him. Ramsay claims police abuse, IAB Sergeant Rick Stetler investigates Horatio, but Ramsay's X-rays... Speculating on a link with the judge's major cases, the team finds Donna's corps in a strangler's peat swamp dumping ground, with vomit which allows a DNA trace to Mathis, but Horatio now considers him a mere pawn...