An old acquaintance, Brandy, hires the guys to find her father. It seems that Lane Preston, who moved to Mexico with his new (and younger) wife Dee Dee, has disappeared. However, before leaving for Mexico, the guys learn from Mama Jo that Dee Dee is a "gold digger." Murray then uses his computer and discovers that, before leaving the country, Lane had sold his restaurant for $400,000. The guys soon arrive in Mexico and find Lane living in a run-down shack. Unfortunately, before they can learn more, Lane is kidnapped. Later, the guys, remembering an exotic drink that Dee Dee liked to order, follow Lane's young wife to the house where Lane is being held. The guys then rescue Lane. Afterwards, Lane explains that a man named Bill Brown had framed Dee Dee for using drugs and, fearing that Dee Dee would go to prison, Lane had given all his money to Brown. Based on the evidence, the guys believe that Dee Dee is part of the "scam, " however, they are forced to prove her guilt to a disbelieving Lane. Thereby, Murray pretends to be rich and ends up on a "date" with Dee Dee. As expected, Dee Dee soon leads Murray into a trap. The guys then storm Brown's house, rescue Murray, recover the money and capture Dee Dee and Brown. Dee Dee, realizing the consequences of her actions, then decides to testify against Brown. Once back in the United States, Lane uses the recovered money to buy a new restaurant.

When Nick and Cody send Murray off of the boat in order to romance two members of the Contessa's crew, the Boz decides to go to the movies. Once there, Murray meets Connie Moreci, a woman in distress. Murray then learns that Connie, a stewardess, has been on the run ever since witnessing a man kill a friend of hers named Arthur Truman. (Connie was delivering packages from Arthur Truman to his brother Walter.) Murray and Connie then leave the theater only to be pursued by the killer. They manage to escape but are arrested by the police for reckless driving. After being bailed out by Nick and Cody, Boz and Connie return with the guys to the Riptide. They soon receive a call from a man claiming to have information about the murder. Nick and Cody then proceed to the meeting site. Back on the Riptide, Connie, who is a diabetic, opens up Walter's package as she needs a shot of insulin. (Connie had been told that the packages were insulin for Walter, who is also a diabetic.) Inside, they find diamonds. Meanwhile, no one shows up at the meeting site. Therefore, Nick and Cody return to the Riptide only to discover that Murray and Connie are missing. The guys also discover the diamonds as well as a key inside of a candy bar that was in Walter's package. Fortunately, George Bobbitt, the man who killed Arthur and who has kidnapped Murray and Connie, asks the Boz to use a computer to trace Walter Truman. Thereby, Murray is able to get a message to Nick and Cody. Nick, Cody, and Walter (who had met the guys when they were searching Arthur's house) soon meet up with Bobbitt, Murray, and Connie. The guys then learn that Bobbitt, an ex-CIA agent, has been tracing a killer known as "Lynx." Walter then shocks the guys by revealing himself as "Lynx" and killing Bobbitt. The "Lynx" then takes the key and diamonds, locks the guys and Connie inside a building, and starts a fire. However, the guys manage to escape. The detectives then locate Walter based on an impression that the key had made in the chocolate and the "Lynx" is captured.

When a guy named Carter and some of his friends start harassing some of the residents of Pier 56, the guys step in and force them to unmoor their boat (The Endeavor) and leave the pier. Later, Carter takes his revenge by ransacking the Riptide. The outraged detectives then learn that the Endeavor belongs to Dr. Robert Atkins. The guys go to Atkins' house only to find the place surrounded by police. Disguised as pool men, the guys sneak inside and learn that Atkins has been murdered. Quickly leaving the scene when Quinlan arrives, the guys are then surprised to learn that they have a passenger: Sherry Meyers, Atkins' former girlfriend and the police's prime suspect in the murder. Unlike Quinlan, the guys believe Sherry and decide to help her clear her name. (Also, the guys figure that Carter, the Endeavor's recent occupant, is a more likely suspect.) The guys begin their investigation and soon learn that Sid Gorman, Atkins' business manager, had been handling the boat. Meanwhile, Carter meets up with his recently paroled brother Davey. Carter then informs his gang that he intends to take revenge on the Riptide guys before leaving town. The guys then get one step closer to solving the case when they disguise themselves as coast guard investigators and pay a visit on Gorman. Gorman panics and the guys follow the business manager to a vacant apartment. After Gorman notices he is being followed and flees, the guys search the apartment and theorize that Carter Chapman, the apartment 's former occupant, was hired by Gorman to kill Atkins. (Sherry had heard Atkins discussing plans to fire Gorman.) Back at Pier 56, the guys are startled to discover that Carter has stolen the Riptide. Fortunately, since the Roboz is on the Riptide, Murray is able to trace the boat. The guys soon arrive in the Mimi and, after bullets are exchanged, Carter and his men are captured and the Riptide is recovered. As a result, Sherry is cleared of all criminal charges.

After arguing with record company executive Alan Singer. P.C.H. singers Dell and Chip are unfortunate enough to lose control of their car. The resulting accident kills Chip and puts Dell into the hospital. Later, the guys become involved when they are hired by members of the P.C.H. fan club to deliver flowers to the hospitalized Dell. Using his computer, Boz soon locates the private hospital where Dell is recovering. The guys then convince a nurse named Elizabeth Baker to deliver the gift. Unfortunately, Elizabeth is caught in the act and forced to flee. The guys and Elizabeth soon access Dell's medical records and discover that the hospital is performing unnecessary surgery on the singer. The guys then disguise themselves as garbage men, sneak into the hospital, and free Dell. However, an ungrateful Dell is soon killed when he tries to blackmail Alan Singer. (Dell had learned that Singer was responsible for his recent car accident/hospital stay). Deciding to investigate the murder, the guys soon realize that a recent P.C.H. album was not recorded by Chip and Dell. Murray's analysis of the album then reveals that the songs were performed by P.C.H. backup singer Pete Frank. The guys then pay a visit on Singer. In order to cover his tracks, Singer then tries to kill Frank. Fortunately, the guys rescue Frank as well as capture Singer at a P.C.H. memorial service.

In Cambodia, Arms smugglers Marty Valentine and Stu Pittman board a plane headed for the United States. Midway through the flight, Pittman throws Marty overboard. Later, Pittrnan feels confidant that he has gotten away with the crime until he finds an empty crate and realizes that there were some unwanted passengers on board the plane. Unfortunately, Pittman gets a lead on finding the possible witnesses when he sees one of Nick's cards left inside of the crate. Meanwhile, the guys are concerned about the fact that Mick Matthews, a man they arrested while serving as M.P.'s in the army, has been released from prison. The guys concerns soon change when Chin Lee and Mai, Nick's foster sponsor children (who had stowed away on Pittman's plane), arrive hoping to get a heart operation for Mai. However, before they can resolve what to do with the kids, the guys are hired to deliver a package. Unfortunately, the package delivery ends up being a trap and the guys are almost killed when another helicopter attacks the Mimi. Using their detective skills, the guys soon learn that it was a pilot named Stu Pittman who tried to kill them. They then go to find Pittman and overhear mobster Sam Valentine wondering about the disappearance of his son Marty. A gunfight then ensues and the guys are unable to capture Pittman. In the meantime, Valentine decides to pay a visit on the guys. Fortunately, the timely arrival of Mick Matthews, who is not upset but is actually grateful for his incarceration, allows the guys to escape from Valentine. Then, based on some information that the kids had overheard, the guys decide to stop Pittman's next arms deal. At the same time, Murray tries to enlist the aid of the police. However, the Boz is forced to assault Quinlan. As a result, an angry Quinlan pursues Murray and arrives just in time to arrest Pittman and Valentine. As the episode ends, Mai receives her heart operation.

Dragged into attending a singles party by Murray, Cody is surprised when he actually meets an attractive and interesting woman named Sheila Hayward. Later, after learning that Cody is a private investigator, Sheila enlists his aid in finding Marcy, her missing sister. The guys accept the case and soon proceed to Marcy's former apartment. They are then shocked to discover that the apartment is filled with numerous violent sexual devices. They also find information that seems to indicate that Marcy is a prostitute and has been working at the Leather Castle. Following up on their lead, the guys follow some men leaving the Leather Castle and see Marcy meeting with Bertane, the Castle's owner. Unfortunately, a gun fight ensues and Marcy escapes from Bertane as well as the guys. In response, Bertane soon kidnaps Sheila and injures Cody. Meanwhile, Murray, having been curious about some inconsistencies in Sheila's story, discovers that there is no Marcy and that Sheila, suffering from a split personality, is both women. While Cody is recuperating in the hospital, Nick and Cody go to the Leather Castle. Fortunately, the two detectives are successful in their endeavor and Sheila/Marcy is rescued. Later, Cody pays a visit on Sheila in a mental hospital. However, any future romance is left in question as it is unclear who Sheila will be after her treatments.

A visit from Melba Bozinsky P.H.D., Murray's historian sister, prompts the guys to try to prove her theory that Hitler had established a port on the United State's west coast during World War II. (Melba needs to obtain proof as an article outlining her initial findings was rejected by publisher Ted Cardwell and editor John McMasters.) With the help of Heinrich Von Schlauser, a friend of Melba's, the guys begin their investigation by trying to locate a German U2 boat that supposedly sunk somewhere in the area. However, while searching, the Riptide is attacked by a man in a helicopter. Fortunately, they manage to escape on the Ebbtide. The guys soon discover that the helicopter was rented by a man named John McMasters. Later, after defusing a bomb that was left on the Riptide, Melba realizes that McMasters works for the company that rejected her manuscript. With Cody on the Ebbtide and Nick in the Mimi, a trap is set for McMasters. Thereby, McMasters and Cardwell are captured. However, although they admit they were responsible for the helicopter attack on the Riptide (as they wanted to find a supply of gold that is supposedly stored on the U2 boat), they deny any knowledge of the bomb. Nick and Cody then realize that Heinrich must have been behind the bombing. Meanwhile, Heinrich, a Nazi that had been part of Hitler's plans, kidnaps Murray and Melba in order to prevent anyone from recovering evidence of his past actions. Fortunately, Nick and Cody soon arrive and capture Heinrich. With all the loose ends tied up, the guys are then able to help Melba recover the U2 boat. Surprisingly, instead of gold, the boat ends up containing plans of the Normandy invasion. [If the boat had not been sunk, the Germans might have won World War II.]