After going behind his friends' backs and stepping into the Quantum Leap accelerator, Dr. Ben Song finds himself in the body of a getaway driver in the middle of a heist.
Ben is blasted into orbit as a member of the shuttle Atlantis crew — but saving the life of an astronaut is just the beginning of his mission. Back in 2022 distrust causes a rupture in the team, and Magic and Jenn search for Al Calavicci's daughter.
Ben leaps into a prize fighter in 1977 Las Vegas, and learns that the man has romantic and family complications. Meanwhile Ian shares a theory on Ben's unseen plan, and Janis confronts her mother.
Ben finds himself an aged gunslinger in the Old West town of Salvation, where the locals are depending on him to save them from a dangerous outlaw who has been hired by the railroad to drive the townsfolk away. In 2022 the team is visited by an inquisitorial Congresswoman.
Ben leaps into a man whose marriage is falling apart ... moments before the great San Francisco earthquake of 1989. While Ben and Naomi search for their son in the wake of the disaster, the team in 2022 attempt to discover who else is leaping through time.
Ben leaps into a priest who has been called to a Depression-era home to perform an exorcism on a young woman, and looks for some explanation to her condition other than demon possession. Addison is sidelined by a glitch in the imaging chamber.
Ben leaps into a 16-year-old who is lost in the woods would a group of troubled teens who have just escaped their school. After Ben receives a warning from Janis the team finds a way to track her down, only to be sidelined.
While Addison wrestles with new revelations about why Ben leaped, Ben finds himself playing bodyguard to a pop superstar who is being targeted by someone close to her.
Ben lands in the body of a Seattle doctor in 1994, where he must save the lives of three ER patients – and take on the hospital bosses about the use of a drug he knows to be dangerous.
An explosion at a nuclear reactor in 1962 causes Ben to leap into one person after the next in an attempt to avert a catastrophe that was covered up by the government.
Ben leaps into a high school basketball coach who inadvertently turns his transgender daughter's life upside down by putting her into a game. Meanwhile, Magic and Jenn follow a new lead they hope will show them who told Ben to leap in the first place.
Ben leaps into a member of an Indian family whose restaurant is going to burn down, and finds out how deep the family's problems go. Ian reaches out to someone from his past after learning something unsettling about the future.
When Ben leaps onto a naval battleship on maneuvers in the South China Sea, Addison is convinced she has the opportunity to undo her father's fateful decision to ignore an incoming distress call that cost the lives of sailors on an American submarine.
As a public defender Ben decides to go to trial to defend a young man accused of murder, and Jenn takes her legal expertise into the imaging chamber to help him.
Ben lands in a psychiatric institution in 1954, where he has secretly been hired to help a young women unjustly committed by her husband to escape. But his mission is complicated when another leaper arrives.
Ben is shocked to arrive at his future destination, where the future Ian gives him what he needs for his final leap: 2018, in the earliest days of the revived Project Quantum Leap, with Leaper X targeting Addison.
