'Orphan Black' season 4 episode 4 spoilers: Sarah allies with an ex-enemy in 'From Instinct to Rational Control'

In Season 4 Episode 4 of “Orphan Black,” Sarah (Tatiana Maslany) will make a unique bond with her former nemesis with the goal of taking down the same enemy. Alison (Kendall Malone), Felix (Jordan Gavaris) and Donnie (Kristian Bruun) will also embark on a mission to get more details about Neolution.

Spoiler alert! This article contains “Orphan Black” spoilers. Read on if you would like to know what happens next before the new episode airs.

The episode synopsis states that Sarah realizes that her goals have become the same as her former enemy, so she creates an unusual alliance with her with the objective of reaching the head of Neolution. In the meantime, Alison sends Felix and Donnie to breach a Neolution fertility clinic that Beth previously investigated. At the laboratory, Cosima and Scott (Josh Vokey) get a surprise delivery from Alison. Rachel also grows closer to Charlotte, while Susan Duncan will have to make a crucial decision.

The promo video for the next episode, titled “From Instinct to Rational Control,” hinted M.K.’s intentions and the possibility of another clone appearing. Felix and Donnie were seen executing their plan. Sarah may also have another huge discovery. The clip also showed Sarah asking Ferdinand what he wants. He allegedly wants her to reveal her source so that they both know what they will need for their agenda. Sarah also found out some shocking news about the new clone, M.K.

Helena was featured consoling Donnie, after he was required by Alison to pretend to be a gay couple, with Felix as his partner, so that they could infiltrate the fertility clinic. Finally, M.K. was shown doing her own investigation about another clone.

According to Entertainment Weekly, the show creators provided some details regarding Delphine’s (Evelyn Brochu) absence. Graeme Manson said that Cosima is still struggling with the disappearance and will continue to struggle through the current season. Delphine’s absence will be part of the mystery and the challenge for Cosima will be to unravel answers. More about M.K. will also be shown, most likely including her deepest and darkest secrets and intentions.

“Orphan Black” Season 4 Episode 4 will air next on May 5 on BBC America. It also airs on Syfy Australia. More updates and details are expected soon.