The letter-bomb murder of a Navy intelligence officer interrupts McGarrett's annual naval reserve duty and involves him in another Wo Fat (Khigh Dhiegh) plot. Harry Guardino, David Birney, Lloyd Bochner and Donna Mills guest stars.

NOTE: Shown in syndication in two parts.

Escaped convict Charlie Bombay (Charles Cioffi) holds a wounded McGarrett hostage after their plane goes down in a severe storm.

NOTE: Bombay was played by Albert Paulsen in Season 2 ("Just Lucky, I Guess") with his first name spelled "Charley" in the credits.

McGarrett searches for a missing English nobleman (Murray Matheson) suspected of passing secrets to enemy agents. Juliet Mills and Dan O'Herlihy (brother Michael O'Herlihy directed the episode) guest star.

A murder sends Five-O in pursuit of a Las Vegas courier (Susan Dey). Andrew Prine and Marc Singer guest star.

Five-O investigates a radical terrorist group smuggling a surface-to-air missile piecemeal. George Takei, John Colicos and Constance Towers guest stars.

McGarrett allows rebelling convicts, led by his old enemy Honoré Vashon (Harold Gould), to try him for murder in exchange for hostages.

NOTE: This episode is the sequel to the three-part "V for Vashon" episode from Season 5.

A scientist (Pat Hingle) demands immunity for a defecting Asian physicist (Soon-Teck Oh).

McGarrett protects a singer (Lois Nettleton) who was a witness to a mob hit.

The murder of the airplane seatmate of Danny's aunt (Helen Hayes, James MacArthur's real-life mother, who received an Emmy nomination for Outstanding Lead Actress in a Single Performance for this episode - the show's final Emmy nomination) is linked to abandoned bank accounts. Charles Durning also guest stars.

A high-school vice principal (Jack Cassidy) uses a submarine to recover smuggled narcotics.

A warehouse burglary investigation turns up unusual loot...and an interwoven connection between the young burglar, his girlfriend/accomplice, and her businessman father. Simon Oakland, Kathleen Beller and Richard Hatch guest star.

An investigative reporter unearths a seven-year-old murder case. Eileen Heckart guest stars.

The investigation of a stabbed college football star points to a gang-rape cover-up and a U.S. Senator's son. Like Season Six's "Nightmare in Blue", this episode is notable for being one of television's earlier expositions of rape victim blaming. Adam Arkin and Richard Masur guest star.

McGarrett's probe of Asian art smuggling grinds to a halt when he is charged with possession of one of the items. Edward Asner and John Fujioka guest stars.

NOTE: Asner would reprise the character 37 years later on Hawaii Five-0 episode "Kalele" (Season 2, Episode 19)

A mentally unstable young man steals a deadly nerve gas to be used during the visit of a foreign head of state.

An aged Japanese importer, an ex-spy who may have known the location of a fortune in gold, is slain. Don Porter, Lew Ayres and Mako guest stars.

The airtight murder case against a racketeer crumbles when McGarrett learns a witness duped him. Henry Darrow guest stars.

NOTE: Introduction of Amanda McBroom as HPD officer Sandi Welles.

Five-O investigates the arson of a new building. Allan Arbus and Robert Hogan guest stars.

A murder victim's roommate (Lee Purcell) puts herself in danger to help catch the killer.

NOTE: This is the final onscreen appearance of Peggy Ryan in the role of McGarrett's secretary, Jenny Sherman.

Five-O goes after those out to destroy a sugar plantation owner's crop with a special moth larvae. Richard Kiley and Paul Shenar guest stars.

Terrorists lock an industrialist's son in an underwater capsule with a limited air supply and the U.S. Coast Guard is enlisted to help in the search. Bruce Boxleitner, Liam Sullivan and Peter Boyd guest star.

Five-O investigates the kidnapping of the wife of a wealthy land developer. David Huddleston guest stars.

The theft of gold leads Five-O to a half-way house for juvenile offenders. Barbara Baxley, Tommy Sands and Rudy Ramos guest stars.