Now that Castle and Beckett have finally given in to their true feelings for each other, how will it affect their work together? As they try to keep their new relationship under wraps from their co-workers, the unlikely duo must track down the murderer of Beckett's mother, find the perpetrator of a major conspiracy and untangle a line of investigation that links Castle to a ritualistic killing.

• Nathan Fillion
• Stana Katic
• Molly C. Quinn
• Jon Huertas
• Seamus Dever
• Susan Sullivan
• Tamala Jones
• Toks Olagundoye