While McGarrett sits in prison awaiting trial for the murder of the governor, Danny brings him a surprise visitor to help clear him. Meanwhile, Kono is suspended from the force, pending an internal investigation.

Gov. Denning assigns Officer Lori Weston to Five-0 to make sure McGarrett and team follow the new rules set by him and also apply her excellent profiling skills to the task force. Meanwhile, as Five-0 investigates the kidnapping of a teenage paddleboard champion, Internal Affairs Capt. Vince Fryer continues his interrogation of Kono.

McGarrett and the Five-0 search for a busload of kidnapped school children as well as the people responsible.

When the team almost causes an international incident, Lt. Gov. Denning decides that one of them should be fired; Chin Ho faces the harrowing task of choosing a Valentine's Day gift for Malia.

The team is directed to investigate when a prostitute is murdered in a Congressman's home, who is nowhere to be found. Danny has his own drama as the custody hearing regarding Grace goes to court.

In an update of an episode from the original series, Five-0 tracks a killer targeting cops… and McGarrett is next on the list.

McGarrett and Grover must work together to protect national security after they are tasked by the Governor to serve a warrant to a young computer hacker.