Following a car accident, Detective Michael Britten regains consciousness and finds himself in two opposing situations; the first in which his wife Hannah dies and his son Rex survives, and the second in which Rex dies and Hannah survives.
Michael attempts to reconnect with Rex in one reality, while in the other, he attempts to comprehend his wife's feelings for losing Rex. As Michael investigates the death of the homeless man Bernard Mackenzie, a witness informs him and his colleague Vega that he has seen a little guy at the crime scene.
Rex is abducted by a fugitive felon whom Michael apprehended ten years ago. Due to an inquiry in Michael's alternate world, he misses an event commemorating his deceased son. In both realities, Michael's mental health starts to be called into doubt by everyone around him.
Michael comes across Rex's old babysitter Kate while investigating a suicide case at an elite yacht party. To Michael's surprise, Kate reappears in another case that he is working on after that, but this time as a suspect.
As his investigation methods are called into question, Michael Britten becomes accused in the case on which he is working. Hannah contemplates leaving Los Angeles and moving to Oregon to pursue her education. Britten receives an unexpected call.
Michael suddenly finds himself teaming up with Dr. Lee while working on a hostage case with Vega. After Rex presents his girlfriend Emma to Michael, Bird speaks with Michael about his lack of concentration and sleep.
As the Brittens carry on with their plan to relocate to Portland, Oregon, Detective Michael Britten is shocked to hear a voice at the drive-thru of Ricky's Tacos restaurant, telling him that he cannot leave Los Angeles and move to Oregon.
In Michael's reality where Hannah is alive, he gets ready with her to move to Oregon. While in his other reality, Detective Britten assists a couple in finding a new life in the witness protection program.
As a football match between an LA university and a Seattle one takes place, a fan of the former's team is found dead, after which his brother identifies his body and helps Michael in finding the murderer. In Michael's world with Rex, a woman dies in a fire accident and he investigates the situation.
When a robbery goes wrong and results in a double murder, Michael and Bird set out to look into the matter. Hannah deals with a difficult issue with Rex's girlfriend, Emma, as she goes with Michael to visit Emma's family.
Britten's ability to control both worlds is disrupted by an odd dream. Moreover, he is taken aback when he finds that an officer at his station made an attempt on his life. Hannah requests that Michael talk with Emma's father about her pregnancy.
As Michael tries to obtain proof that Hawkins attempted to murder him, he also discovers that Carl Kessel was involved in the scheme. Despite doubting Michael's mental health, Bird assists him in both of his worlds.
In order to conceal her role in the conspiracy, Captain Harper assassinates Captain Kessel. Michael begins to understand the truth behind the accident. Dr. Lee and Dr. Evans have a debate that leaves Michael at a crossroads.