It's been nearly 30 years since Dr. Sam Beckett stepped into the Quantum Leap accelerator and vanished. Now, a new team, led by physicist Ben Song (Raymond Lee), has been assembled to restart the project in hope of understanding the mysteries behind the machine and the man who created it. Everything changes, however, when Ben makes an unauthorized leap into the past, leaving the team behind to solve the mystery of why he did it. At Ben's side throughout his leaps is Addison (Caitlin Basset), who appears in the form of a hologram only Ben can see and hear. She's a decorated Army veteran who brings level-headed precision to her job. At the helm of the highly confidential operation is Herbert Magic Williams (Ernie Hudson), a no-nonsense career military man who has to answer to his bosses who won't be happy once they learn about the breach of protocol. As Ben leaps from life to life, putting right what once went wrong, it becomes clear that he and the team are on a thrilling journey.