Sarah Is Infected With A Parasite On 'Orphan Black' & Neolution Is Getting Even Nastier

Remember that nasty worm that Dr. Nealon tried to regurgitate into Delphine's mouth before she killed him in the Orphan Black Season 3 finale? The same worm, apparently, that Neolutionists are planting inside the mouths of their followers — and then harvesting by murdering the hosts and cutting off their cheeks? We still have no idea what exactly they are or what they do, but they're certainly not good news. At least none of the characters we know and love have an icky "maggot bot" implanted in their cheek, amiright? Oh wait. Now Sarah's infected with one of the parasites and things just went from bad to worse for her on Orphan Black Season 4.

The show's central clone made this gruesome discovery after a frantic episode spent retracing Beth's steps. Following up on the cliffhanger from the season premiere, Sarah, Kira, Siobhan, and Kendall were forced to flee Iceland after a call from M.K. alerted them to the fact that the Neolutionists had somehow been tipped off to their location. Defying common sense because otherwise there would be no show, Sarah & Co. burned down their Nordic hideout and returned to the (still anonymous) city from which they'd fled, meeting Cosima and Scott in their new underground lab-slash-batcave.

Since Beth was the only clone who'd had previous contact with M.K., Sarah and Art stopped by the deceased cop's apartment for clues. On the video feed of the camera that Beth installed to spy on Paul, Sarah saw the pregnant Neolutionist from the series premiere. That led her to Club Neolution — just like Beth before her — where, conveniently enough, a man named Dizzy mistook her for M.K. and showed her a video clip of the now-infamous worms. (Turns out they have a defense mechanism that causes them to suddenly shoot out tendrils and kill their host if they're tampered with.) Although the man quickly realized that Sarah was not in fact M.K., she managed to steal his phone and use it to find his meeting place with the sheep-masked clone.

Of course, the hyper-paranoid M.K. didn't actually show up to the meet in person, but called Sarah on the man's cell phone while spying on her through the laundromat's security camera from a car outside. M.K. refused to divulge anything too significant, telling Sarah that the truth would kill her the way it killed Beth — but that the reason Beth killed herself had at least something to do with those freaky implants. And as if on cue, the two EMTs we've seen surgically removing the worms, Frank and Roxie, walked into the laundromat.

Although they held her down and waved a scalpel in her face, after peeking in Sarah's mouth they realized she wasn't the clone they were looking for and left just as quickly as they came. In a panic, Sarah returned to her hideout and did the one thing she's never done before — scared Kira — grabbing the young girl's face and trying to forcibly look inside her mouth. Siobhan restrained her, but when Sarah begged her foster mom to examine her own mouth, they both saw to their horror something moving inside Sarah's cheek, apparently implanted in there sometime while she and Kira were being held by Dyad.

Are all the other clones infected with the Neolution worms? Is Kira? What purpose do they serve? And will they all be able to remove them in time before one of the worms explodes and kills its host? Season 4 may have so far toned down the convoluted conspiracy subplots, but it hasn't lessened up the tension — and this new threat may be the ickiest one yet.

Images: Ken Woroner/BBC America (3)