When an 8-year-old is found dead on the Appalachian Trail, the team searches the forests for a man targeting children.
Castle considers how to fix his relationship with Beckett and finish writing his book, but the pair must investigate a dead man tangled in tree limbs.
The remains of a couple are found in a cave; Brennan re-evaluates her relationship with Booth when his girlfriend makes a surprise visit.
When a doctor is found murdered at a golf course, the team searches among his staff and patients for a suspect; Cho becomes the new team leader.
Information about Huck's past is revealed; not realizing that someone could be watching, Fitz and Olivia have an emotionally charged conversation; Cyrus becomes increasingly suspicious of Jake.