It is strongly implied throughout the episode that Lorna/Polaris' father is Magneto. Though he was never name dropped, it was mentioned in a flashback between Lorna and Marcos that her father was member of the Brotherhood as well as described as a "monster." In the comics, Magneto is the leader of the Brotherhood and Polaris' father.
The first episode since eXploited not to feature Sophie Frost and Phoebe Frost along with Esme Frost.
This episode introduces Dr. Madeline Risman, played by Kate Burton. Dr. Madeline Risman was the former assistant of Otto Strucker (Reed's father), who was played by Raymond J Barry in earlier episodes. Kate Burton and Raymond J Barry both were guest stars on an episode of The Closer (S7 E5 "Forgive Us Our Trespasses"), where they played daughter/father.
In this series, "Morlocks" are the mutants who live in the tunnels beneath the city. The term "Morlocks" originated in H. G. Wells' 1895 novel "The Time Machine". In a post-apocalyptic world the Morlocks live underground while the Eloi live on the surface