The 2nd Mass arrives at a safe haven. As the two groups make plans for the final assault on the Espheni, the 2nd Mass begins to realize that things aren’t exactly as they seem.

Mike teams with Jack Soloff on a case. Esther Litt returns to P.S.L. in hopes of discreetly solving a problem, and Donna and Harvey try to return their friendship to normal.

Injured, Tom takes refuge with a unique family who has distanced themselves from the fight, giving him a glimpse of life without war. Hal and Isabella’s romance grows as they search for a missing Tom. Meanwhile, The 2nd Mass locates an Espheni device that could be a linchpin to winning the war… if they can figure out how to use it. And Maggie makes a decision that has consequences for her and the entire 2nd Mass.

With the Synths now in captivity, Hobb attempts to extract Elster’s consciousness programming from their brains. There ends up being one final piece of the puzzle missing that nobody, including Leo could ever have imagined though. The devastated Hawkins family come to realise much Mia mean to them and their courage is put to the test as they take on Hobb and his forces in an effort to save the Synths from their imprisonment.

Harvey reels from Dr. Agard’s revelation about the root of his panic attacks; and has to make a tough decision in a case that touches a nerve. In other events, Mike and Louis take over responsibility for Harvey’s oldest client; and Donna tries to make Rachel’s dream wedding possible.

The 2nd Mass leaves Chinatown en route to what they hope will be the final Espheni battle. Along the way, they encounter a deranged and desperate gunman who takes Weaver hostage. Meanwhile, Tom sets off to rescue Hal from Pope and his dangerous group of survivors.

Rejected and alone, Karen sets out to George’s house in search of Niska. Meanwhile, Pete is determined to find out who Karen really is, but his enquiries reveal a truth stranger than he could ever have imagined. The hunted synths gather at the Hawkins, grateful to Laura and family for providing refuge. As humans and synths live alongside each other in peace, could this be the harmonious future that Leo and co have longed for? But as Hobb gets closer, it may be too late for them to find out.

When Harvey’s bitter rival Travis Tanner turns up on the other side of a case, claiming to be a changed man, Harvey and Mike must decide whether to believe him – or bury him. As Harvey’s sessions with Dr. Agard continue, she links his personal stake in the Tanner fight to issues from his past. Meanwhile, Jessica tasks Louis to make things right with Harvey, and with Rachel and Donna’s help he devises a plan – one which could make an enemy of the formidable Jack Soloff.

A mission to procure vehicles and fuel goes awry. Cochise shares troubling news with Anne that will test both her medical and leadership skills. Anthony’s mental stability and his loyalties are brought into question. Meanwhile, a desperate Pope takes things into his own hands.

The fractured Hawkins family reaches its lowest ebb, with dad Joe in exile, and Mattie, Toby and Sophie tired of their parents’ lies. As the situation reaches breaking point, Laura decides it is time to tell the truth, and her confessions has incredible consequences for household synth Anita. Meanwhile, Karen finally discovers `killer synth’ Niska’s whereabouts, and a joyful reunion for the runaways is cut tragically short when a brutal betrayal forces one of their number to make the ultimate sacrifice.