A Leap for Lisa

A Leap for Lisa is the season finale for season four of the television series Quantum Leap; it tells the story of Sam leaping into a younger Al.

Sam leaps in to find himself on a beach with a beautiful naked woman emerging from the ocean kissing him. He quickly realizes this is a dream when he wakes up.

Sam's host is a Navy ensign nicknamed "Bingo". Bingo is currently under guard as a suspect in the rape & murder of Marci Riker, a superior officer's wife. He has an alibi though; on the night of the murder, he was with his girlfriend Lisa (guest star Terry Farrell), an enlisted nurse serving on the naval base.

Lisa is eager to prove Bingo's innocence but doing so could ruin their careers, as she is married, and Bingo is an officer. Sam assumes that he is there to prevent that, and discourages her from telling anyone about the alibi. He is confident he will find some other way to prove his innocence. After an unusually extended absence, Al finally arrives, and reveals that "Bingo" is actually a younger Al Calavicci; Al accounts for his delayed appearance by explaining that he had been thrilled to encounter his younger self in the Waiting Room.

At first, Al and Sam are both highly amused by the synchronicity of the leap, but when Al learns of the date, he is too late to prevent her from dying in a car accident. She was distraught over Al's predicament and lost control while drying away tears. Al tells Sam that in the original timeline Lisa told Sam's lawyer Commander Dobbs about his alibi. Dobbs planned to use it only as a last resort and when Lisa died he convinced the Navy to drop the charges and not prosecute Al for his personal conduct. Older Al isn't mad at Sam for the mistake though, because now nobody will be gossiping about her over her grave.

Commander Riker, the deceased's husband, comes to see Sam and says that he understands that his wife loved sleeping around with the men under his command. Al's best friend even informed Dobbs about this, saying that Al was the only one who ever refused her advances, because of Lisa. Riker says it didn't bother him as they both had their perversions and that left only pleasure in the marriage. He then claims he saw Al rape and kill his wife from a cliff above the beach and promises to testify to that. He tells Sam he will make it his mission to see him die in the gas chamber.

At trial Riker repeats these details. Dobbs questions his ability to clearly identify a man of similar build and uniform from 200 feet away in the dark, but Riker is adamant. He followed Al's car after he saw his wife enter it at the officer's club.. When questioned about why he did nothing to stop the attack, Riker bitterly replies "Because she deserved it". Sam thinks he's free and clear because that testimony will ruin Riker's career, likely as a coverup to him being the true killer. Dobbs doubts this saying he is certain Riker believes what he testified too, and the judges will believe it too.

At that moment Al appears in a panic. The odds of him being executed are rising by the second. Suddenly he disappears from the future and is replaced by Edward St. John V, a more formal project observer, played by Roddy McDowall. Edward tells Sam that Al was convicted and executed after 3 years in prison. Sam remains the only person left who knows the original timeline. Edward runs calculations and determines the key to Al's innocence lies somewhere in his car. Sam convinces his guard to let him search it, where he finds a cigar. The moment he does, Al replaces St. John, with no memory of the brief discrepancy. Sam tells him that he didn't find anything but his cigar, but Al tells he didn't smoke those until Vietnam. The cigar matches those smoked by Al's best friend and wing man, "Chip" Ferguson.

Sam asks Chip to meet him in his quarters. Chip tells Sam that he dropped Al and Lisa off at a motel the night of the murder, then drove to the officer's club in Al's car. He saw Riker abusing Marci in the parking lot and gave her a ride. She was drunk and wanted someplace where she could run naked. They had slept together before, and he said he was in love with her. While Marci was undressing he came on to her, but she rebuked him. Chip tried to force himself on her, but he didn't rape her and she fell, striking her head on a rock and dying instantly. Chip is truly sorry and says he was going to turn himself in had Al been convicted. He asks what Sam plans to do and Sam says he has an idea.

Sam tells Al to talk to his younger self again, and reveal his true identity. He directs the older Al to send his younger self into the quantum leap accelerator. It will only be possible for Bingo to leap into himself, so they should calibrate the accelerator to put him as close to the night of the murder as possible. Although they are sure that most events he will not remember, old Al gives Bingo simple instructions; Do not let Chip out of your sight on the date of the murder. Young Al is sent back in time, but they aren't sure what date he lands at.

Sam & Al wait in his quarters for something to change. Sam gets the idea to look outside his room. The Marine guard has left. They realize that a Marine would never leave his post, and there must have been no death. At that moment Chip arrives with a surprise guest for Al. It is Lisa, who has gotten off work early and wants Al to buy her a drink. As he was never under suspicion of murder, she was never distraught enough to lose her control of her car. With both Marci & Lisa alive, and older Al marveling at the new timeline that's been created, Sam leaps away smiling.