Orphan Black - Season 3 - Eps 4: Newer Elements of Our Defense
Mark is taken down in a Prolethean shoot-out and Sarah must step in to help. But as Sarah gathers intel that puts her on the trail of the original Castor DNA, a familiar foe is not far behind. While Helena continues to toil in a faraway military compound, it is ultimately Sarah’s fate that will hang in the balance as she tries to save her sister. Meanwhile, Gracie is cast out from the Prolethean fold, and Alison and Donnie come face-to-face with unhappy drug lord, Jason Kellerman.
About Orphan Black

Title: Orphan Black
First Air Date: 2013-03-30
Last Air Date: 2017-08-12
Status: Ended
Rating: 7.804/10 (from 1283 votes)
Language: EN
Seasons: 6
Total Episodes: 50
Network: Space BBC America
Genres: Drama, Sci-Fi & Fantasy
Production Companies: Bell Media, Temple Street Productions, BBC America
Synopsis
A streetwise hustler is pulled into a compelling conspiracy after witnessing the suicide of a girl who looks just like her.
Cast

Tatiana Maslany
Sarah / Cosima / Alison / Helena / Rachel

Jordan Gavaris
Felix 'Fee' Dawkins

Josh Vokey
Scott Smith

Maria Doyle Kennedy
Siobhan 'Mrs. S' Sadler

Ari Millen
Mark / Rudy / Miller / Ira

Kevin Hanchard
Detective Arthur 'Art' Bell

Kristian Bruun
Donald 'Donnie' Hendrix