With tensions rising between Castle and Beckett, Castle finds himself a new partner — Detective Ethan Slaughter (guest star Adam Baldwin, “Firefly”), a tough and colorful cop from the city’s…

The team investigate a glowing body. Hodgins proposes to Angela — several times.

Ted agrees to let Barney spice up his love life, and ends up on a crazy adventure of flying to Philadelphia, encountering the law and visiting the Liberty Bell.