A teenager (Astro) whose brother was recently murdered is identified as the latest person of interest; Finch fears that his ex-partner's son is getting close to discovering the machine.
Sherlock must take the stand and defend his career after an investigation goes horribly awry, threatening his and Watson's future with the police department.
Buffy's mother gets trapped inside Sunnydale High School when a vampire named Spike arrives in town and launches an attack against the Slayer.
The winner is announced in the competition between Alicia and Cary.
Reed and Archer are captured and face execution when they return to a pre-warp planet to retrieve a communicator.