News of the `Killer Synth’ finds its way into the media, causing widespread panic, and placing Karen under even more pressure to track down the alluring fugitive Niska. However, it seems there may be an ulterior motive to her hunt for the murderous synth. Meanwhile, the Hawkins debate whether to keep Anita in light of their recent discovery that she is not quite as `new’ as she seemed, and while Joe worries his domestic synth might inadvertently reveal his secret, Mattie’s decision to place her trust in Leo could put an end to the family’s arguments.

Harvey brings some star power to his ongoing conflict with Jack Soloff – a conflict that Louis and Donna can’t seem to stay clear of. Mike brings in Robert Zane to co-counsel a case, pitting his instincts as a lawyer against his desire to stay in his future father-in-law’s good graces. And while Jessica mediates between Mike and Zane, she tasks Rachel with an unusual assignment.

A surprise skitter attack leaves the 2nd Mass without food. In desperation, Maggie, Ben, Pope, and Sara go on a dangerous mission hoping to find supplies.

Laura feels vindicated when Mattie tells her that she has seen Anita acting strangely. Laura insists that the family take Anita for testing and they’re shocked to discover she’s 14 years old. After meeting Leo through the Headcracker forum, Mattie thinks she might have an idea. Pete becomes stir crazy, stuck in the house with Simon.

Harvey searches for a replacement for Donna. Mike takes a case as a favor, which he must justify to Jessica – while Rachel’s father, Robert Zane, offers some unsolicited advice about Rachel’s engagement to Mike. And Louis is embroiled in surprising money matters, while an up-and-coming partner, Jack, makes his presence known to Jessica, confronting her about whether Harvey’s way of doing business is beneficial to the firm.

On the heels of Tom and Lexi’s successful albeit tragic mission to destroy the Espheni power core on the moon, we pick up with Tom’s life hanging in the balance as his Beamer drifts into space. While onboard the beamer, Tom encounters a surprising guest who urges him to find his inner warrior. Meanwhile, back on earth, Anne reluctantly steps into Tom’s shoes to help lead the 2nd Mass in his absence. Against all odds, Tom makes a miraculous, yet mysterious return to earth. Once reunited with the 2nd Mass, Tom shares a new plan for winning the war. The Espheni, for the first time, are on their heels, and the 2nd Mass will not rest until they are gone from this planet for good.

Laura finds herself at odds with her family when she tries to return Anita to the shop, but Laura is begrudgingly forced to keep her when Anita saves Toby from a near-fatal road accident. Joe suggests that Laura is imagining Anita’s strange behaviour, but he can’t help noticing how human Anita appears when he has to check her for damage. George seems to have submitted to Vera’s joyless routine, but he is actually hatching a daring plan to escape with Odi. Pete and Karen investigate a murder at a brothel, but after Pete’s hot temper earns him a suspension, he finds himself stuck at home with Simon.

Pearson Specter Litt has scored a hard-fought victory, but the fight has left the firm shaken. Although she avoided jail time, Donna has left Harvey after more than a decade of working together. She is now working for his long-time rival Louis. And while Jessica readjusts to being single, Mike and Rachel are giddy after his marriage proposal

Laura is suspicious of Anita, and feels threatened by her presence. Hobb holds Fred prisoner in his facility, but while Hobb’s superiors marvel at this unique specimen, Fred voices his fears about what this means to humanity. After a violent incident, Niska escapes her brothel prison, pursued by Karen and Pete. Leo’s quest for information takes him to increasingly dangerous places. George’s worst fears are realised when the health service give him a new Synth, Vera, who he immediately despises.

As Clone Club races towards the truth, Castor and Topside force Sarah to make uneasy alliances. Meanwhile, Kendall may be the key to stop Castor; the sisters appear to be thwarting their most dangerous foe.