There was much hype about the coming of the clone M.K. whose side she is on was unclear until the last episode where her true motives were revealed. Although Ferdinand's alliance is also constantly in question, his relationship with Sarah will figure in the season as they start working together on "Orphan Black" season 4 episode 5.

"Orphan Black" creators John Fawcett and Graeme Manson spoke with Entertainment Weekly about what to expect after the events in episode 4. It was revealed that M.K. is actually Vera, who is one of the survivors of Operation Helsinki. It is suggested that the aborted operation is responsible for the parasitic virus that has infected Sarah.

Fawett shared, "The Helsinki story was of particular interest to me early on in the season, and we actually kind of wrote an entire comic book series around Helsinki and around the character of Vera, who, basically, becomes M.K." That being said, viewers have certainly not seen the last of the paranoid clone yet.

It's also this discovery that would lead Ferdinand and Sarah to start trusting each other more. Whether or not Ferdinand is someone Sarah should trust will unfold as the season progresses. Fawcett said, "Ferdinand and Sarah have this kind of relationship of being frenemies since the beginning. Ferdinand is not exactly someone that we can entirely trust, but it appears that M.K. isn't either."

He also added, "Going forward, both of these characters play into later parts of the season, so this is just a little building block towards something bigger."

The next episode will also feature the return of Krystal. Krystal first appeared in season 3 where she seems to be one of those unaware of the clone project. She has also shown curiosity about being the clone and her appearance could indicate that she wants to learn about herself and the genetic/cloning program more.

Catch "Orphan Black" season 4 episode 5, titled "Human Raw Material," on May 12, 10 p.m., on BBC.