Following her call from M.K., Sara snaps into action, quickly packing up all of their belongings in their little cabin. Mrs. S tries to calm her down, questioning how M.K. could know that Neolution's found them. Kira looks out the window into the distance and announces that "they" are coming. Sara, Kira, and Kendall Malone rush out while Mrs. S. starts a fire to burn away any traces of their DNA.

Alison, Felix, and Cosima each separately get word that Sarah and the others are back in town. Cosima is visibly distracted, worrying about the missing Delphine's fate.

Sarah, Mrs. S, Kira, and Kendall are smuggled back to Rabbit Comic Book Store in Canada in the back of a van by Mrs. S's friend Benjamin and his people. Kira and Kendall are taken to a safehouse. Kira is upset that Cal will not be with them for a while.

Mrs. S and Sarah are taken to the downstairs area of the comic book shop, which is acting as the "secret lab headquarters" for Cosima and Scott. Cosima greets her warmly. They call Allison and explain the situation with M.K. Alison insists that Beth never told her about M.K., that Beth had secrets to protect them.

Scott explains to Mrs. S that the Hendrixes ponied up the cash to set up the secret headquarters. Most of Dyad was laid off and they are now (apparently) out of the clone game. Mrs. S expresses concern over Cosima's health (Scott says they are working on genome therapy using Kendall's sample) and Delphine's fate.

Alison instructs Donnie not to tell Helena that Sarah and the others are back, because she's taking up too much space anyway.

Art and Sarah meet for lunch at a diner and discuss M.K. He shows her the case file for the last case that Beth worked on, the Neolutionist with the missing cheek and the bisected penis. Art didn't know everything that Beth was working on, so they mutually decide to go to Beth's old flat to check it out.

The flat has been paid up through the end of the year by Paul (a.k.a. Dyad) and Beth's stuff is all boxed up, her family apparently "taking care of it," according to what Art heard from the station.

Alison visits Felix, wondering why he hasn't been answering his calls or hasn't gone to see his family. Alison encourages Felix to tell them what he's been up to, but Felix is hesitant.

Art and Sarah look through the boxes. In a flashback sequence, we see Beth meeting with Detective Duko during a "home visit." She's suspicious, noting that the union doesn't typically do home visits. Duko tells her it's a special situation. He pokes around her house, asking about her copy of Leekie's book. He semi-threateningly warns her against continuing to poke around with high level people after her suspension. Duko tells her he has to keep everyone he cares about safe.

In the present, Sarah finds Leekie's book and shows Art. They realize she was on to Neolution and met Leekie in person.

Donnie takes Helena to a pregnancy appointment, with Helena posing as Alison to use their health insurance. They act awkwardly, trying to pretend to be a married couple. Helena and Donnie see the fetus in an ultrasound and the doctor announces she is having identical twins. Helena says that she has to tell her sestra.

Cosima takes Kendall's blood. Kendall comments on Cosima needing sun and wonders why her DNA is not working to cure her.

In Beth's apartment, Art spots holes in her painting where the surveillance equipment was hidden. Meanwhile, in the bathroom, Sarah finds Beth's drug stash. Sarah realizes that Beth was spying on Paul. In a flashback, Beth takes drugs and puts on a disguise to go to a hotel, taking a gun with her. 

In the present, Sarah and Art watch the video footage and see Beth slowly spiraling, holding the gun on Paul as we saw in the last episode. They also see Trina, the pregnant Neolutionst, visiting Beth. Sarah leaves, saying she's going "back to the beginning of all this shit."

She leaves to get Felix and tells him that she missed him and wants to go to a bar. Felix hints that he wanted his space from everyone. She takes Felix to Club Neolution, so he can let her in around the back, unseen, and they can search for information about Trina.

Donnie excitedly shows Alison the ultrasound photo of Helena's twin babies. Alison is dismissive, wondering how Helena, who is such a mess, will take care of two babies. Donnie asks whether Alison is upset because of her own fertility issues. Alison dismisses that and angrily comments on Helena messing up her crafts room and eating them out of house and home. Donnie mentions that Helena is just trying to be like Alison.

Mrs. S speaks with Cosima, who's smoking medicinal grade weed for her illness, trying to get her to open up about her concern for Delphine. Cosima breaks down and says she misses Delphine so much. Mrs. S comforts her.

Kendall speaks with Scott about her test results. He notes that her results are strange and she confesses that it is leukemia -- she was diagnosed months ago and hasn't told anyone. She asks Scott not to tell anyone and he agrees.

Sarah questions people about Trina. She finds Felix at the bar and he snaps when she asks what he's doing. She ask what's wrong with him, and he confesses that he's looking for his birth family. Sarah tries to convince him that she and the others are his family and that he belongs with them. Felix denies it and then leaves her to head off to the dance floor.

Meanwhile, a bearded stranger approaches Sarah, confusing her with M.K., who he was apparently supposed to meet later that night. He takes her aside and shows her a video discovered by one of his friends, taken in Bogota, of a person with the implanted Neolution tech. The person taking the video pokes at the implant and it suddenly kills the host -- it has a defense mechanism. The man realizes Sarah is not M.K. and asks who she is, she grabs his phone and runs off, using his text messages with M.K. to head to their rendezvous point.

Art watches the video surveillance from Beth's apartment and sees her in disguise, preparing to leave for the hotel. He wonders what she was doing.

Sarah heads to a laundromat to meet MK, who calls her on the bearded man's phone instead. MK is not physically present, instead watching Sarah through a security camera she's hacked. Before speaking with Sarah, she demands that Sarah take off her boots and put them on the counter and put the phone in the dryer (to cut the signal if they are listening in). She explains that she listened in and cast a net to get information on what Neolution was up to, finding Sarah's and Kendall Malone's names. She refuses to speak to Sarah any more, claiming it will kill Sarah the way it killed Beth.

In a flashback (and simultneously with Art watching the same video footage in the present), we see Beth return home from the hotel, shaken and with blood literally on her hands. She finds MK there. MK wonders where Beth was, not having heard from her in four days. She notices blood on Beth's hands and Beth tells her it's not her blood. She tells MK that she messed it all up and they can't fight it anymore. MK begs Beth not to leave her but Beth leaves (presumably to jump in front of the train and kill herself). She gives MK her gun and tells her to go back into hiding, and watch over the others for her.

In the present, Sarah attempts to chase after MK who drives away. As she's readying to leave the laundromat, she is attacked by the two EMTs who restrain her and prod at her mouth. They see something in her mouth and realize she is not MK -- they leave her there.

Sarah panics and returns to the safe house where she anxiously checks Kira's mouth, frightening her and alarming Mrs. S. She demands that Mrs. S check in her mouth. Mrs. S finds one of the Neolution implants in Sarah's mouth, shocking them both.