Castle senses a diary of a P.I from the 1940s found in the effects of a murdered modern-day treasure hunter is the key to finding the Blue Butterfly, a blue-diamond necklace. The team works out the story situated in 1947 in the same, now derelict, music club, involving murder, gangsters, and theft; they work out the true parts and identities of culprits and victims.
Stars: Nathan Fillion, Stana Katic, Susan Sullivan
Director(s): Chuck Bowman
Writer(s): Andrew W. Marlowe, Terence Paul Winter, Shalisha Francis
Genres: Comedy,Crime,Drama,Mystery,Romance