A woman gets the wrong idea from her husband's secretive behavior and fears that he is plotting to murder her. Isaac begins a whirlwind romance with an internationally known singer. A couple suspects that a painfully boring passenger is actually a wanted jewel thief.

(Part 1) The Love Boat sets sail with two famous Hollywood stars, married couple Roz Rogers and Bill Klieg who need to find a balance between their professional and personal lives. An inept team of thieves board the ship and try numerous tactics to steal the Star of Kashmir, an expensive jewel brought aboard the ship by Ms. Rogers. Two childhood friends from a school for the blind meet up on the ship - only one of them isn't blind anymore. But that's not the only secret he is keeping from his friend. A philandering husband looks like he will be found out when he boards the ship with both his wife and his mistress.

(Part 2) The Love Boat sets sail with two famous Hollywood stars, married couple Roz Rogers and Bill Klieg who need to find a balance between their professional and personal lives. An inept team of thieves board the ship and try numerous tactics to steal the Star of Kashmir, an expensive jewel brought aboard the ship by Ms. Rogers. Two childhood friends from a school for the blind meet up on the ship - only one of them isn't blind anymore. But that's not the only secret he is keeping from his friend. A philandering husband looks like he will be found out when he boards the ship with both his wife and his mistress.

Doc's ex-wife hires an actor, who takes his role a bit too seriously, as her fiance; a philandering marriage counselor's wife seeks solace from Captain Stubing; a woman pretends to be her own sister for a reunion with a long-ago sweetheart.

April returns to the ship with her fiancé, a former used car salesman turned manager whom she has known only a few weeks. The crew is certain that the man is scamming her. A couple comes aboard the ship to finish a script before filing for divorce. A man is shocked to run into the daughter he gave up for adoption and her adoptive mother. He agonizes over whether to tell her the truth about her parentage.

Julie worries that her brilliant nuclear physicist friend will never find a man because her intelligence intimidates suitors. She encourages her to act dumb to attract a man's attention. Vicki befriends a wealthy young passenger. While exploring the ship, they discover a stowaway, a young boy who wants to visit his mother in Mexico. A jealous husband terrifies the crew as he constantly threatens the guys, who he suspects are coming on to his wife.

The Virgin Islands serve as a backdrop for the Grand Prix Wine-Tasting Competition, whose winner receives a $25,000 prize.

Julie books Hank to entertain, but he moonlights as a stripper. Isaac tries to set up sad Frank with girls until his ex-wife Jan arrives. Merrill recognizes passenger Jim as a jewel thief and suspects him when a diamond is stolen.

Adam introduces his fifth wife Tania to the crew. Safety inspector Sid takes his job too seriously and sees danger everywhere. Financial group president Ralph tries to talk VP Lydia out of quitting due to bogus rumors about their affair.

The nearness of their homes interferes with Don and Doris' romance. Artist Barbara wants to paint Merrill's portrait - nude. Elderly Frank vaguely recognizes honeymooning Stan from somewhere but can't recall details.