Sherlock uses his powers of deduction to consult on the murder of a young man who is shot upon entering his apartment.
While investigating a death aboard a top-secret naval research ship in the middle of the ocean, the team discover an abandoned ship and a deadly secret.
While Carter closes in on Reese and Finch and the CIA close in on her, the two men investigate a suspicious building supervisor whose number has come up.
Despite being close to losing her job, Maggie manages to make it onto a flight to Rio de Janeiro; Kate is unsure of herself after getting a difficult mission involving a Yugoslav diplomat; Ginny's games don't sit well with Dean.
Dean is shocked when Ginny follows him to Rome; a precocious unescorted minor develops a crush on Colette; Kate faces the dangerous consequences of her connection with Niko.