An entertainer on a cruise ship is killed, and Castle and Beckett investigate while trapped on the ship with the murderer.
When Leonard is set to give the commencement address at his former high school, a canceled flight threatens to stop him giving the speech. Meanwhile, Howard's engineering skills are tested when he and Sheldon try fix Raj's toy helicopter, while Raj plays his parents against each other after his father cuts him off financially.moreless
Charlie and Nolan compete for the attention of a hot grad student. Martin and Ed do a patriotic sham.
When their favorite show gets cancelled, Sam and Cat go to the studio to beg for its return.
While the study group deals with the death of a beloved classmate, Chang finds an opportunity to take control over campus security when the memorial service transforms into a riot.
Pierce throws a party to celebrate his business success, but when his elderly father shows up, he puts a damper on the festivities. Meanwhile, Troy becomes a hot commodity for Vice Dean Laybourne and a janitor.moreless
Robin recounts to a therapist the events that led her to his office. Meanwhile, Ted tries to help Lily and Marshall withtheir pregnancy too much.