Emma and August Booth talk about Henry's book in episode 1x18 "The Stable Boy". From episode 2x03 "Lady of the Lake". From episode 2x10 "The Cricket Game". Appears in 4 more episodes.
The gang returns to the mainland after defeating their enemies and Juliet and Shawn are married right on the pier by El Proveedor.
A cop arrives at the dock where Sam Scott is tied up to look at the body they pulled from the sea. In a deleted scene, Sam is called back to the boat by the police to give a statement after the cop is found dead.
Source: jholden23 — Twitter