Olivia (Anna Torv) is still worried about the effects of the Observer implant on Peter (Joshua Jackson), and succeeds in getting another one from their ally Anil (Shaun Smyth) for Walter to study.
Peter is still trying to track down Captain Windmark (Michael Kopsa) to avenge killing his and Olivia's daughter Etta, using the precognitive abilities of the implant.
He flees Etta's apartment just before Windmark and his associate arrive, and heads to New York City to put his plan into motion.
She finds Peter waiting to kill Windmark, but coaxes him out of it by explaining that Etta remains within them and their memories, showing him the bullet necklace.
"The Human Kind" was written by co-executive producer Alison Schapker and directed by The Practice veteran Dennis Smith.
An estimated 2.7 million viewers watched the episode, and earned a ratings share of 0.9 among adults aged 18 to 49, to rank third in its timeslot.
He also noted another reason of the episode's success, is because "that each individual plot point and character beat that leads up to the big tearjerker finish is well-honed."