Allie MacDonald

With Susan Duncan deposed, Sarah finds herself in the same position as Rachel — under the heel of a new HBIC — causing the archenemies to come together for the greater good. Cosima and Susan butt heads on the ethical implications of human experiments. Meanwhile, when the Hendrixes' legal counsel, Adele, further investigates Donnie’s case, she begins to suspect Felix is keeping deep secrets. Helena’s arrival forces Felix to make a difficult decision.

Sarah realizes her goals have aligned with a former enemy and forms a precarious alliance in hopes of getting to the head of Neolution. Alison heads a mission to infiltrate a Neolutionist fertility clinic that Beth investigated, and sends Donnie and Felix in undercover. Back at the lab, Cosima and Scott receive a special delivery from Alison. As Rachel grows closer to Charlotte, Susan leaves a devastating decision in Rachel’s hands. A desperate Sarah returns to Dizzy needing his help again.

Jason Miller returns to school after waking from a coma and uses his enhanced Alpha ability to control his classmates. When Dr Rosen and Stanton Parish are obliged to team up to bring him in, Rosen uses the opportunity to question Parish too, but does Parish have an ulterior motive?

When a body is found in a compost heap, the victim's history of abusive behavior leads to a varied list of suspects. Walt and the team must cross county lines to track down the killer. Branch looks into Cady's abrupt departure from Absaroka County.

Audrey, Nathan and Duke are lured to a haunted house on Halloween - and become trapped inside. Guest starring Iain Glen.