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.
Holmes and Watson investigate a double-homicide and discover the victims were staging a fake murder at the time they were killed.
Alicia and Diane must constantly rethink their approach when an opposing lawyer keeps changing tactics. Meanwhile, Eli wins a victory in his efforts to protect Peter's image. Maura Tierney returns as Maddie Hayward.
