Loose
performed by Benny Blanco & Spank Rock
(Song)

Castle and Beckett are called to look into the murder of a winner of 117 million dollars in the lottery who was found dead in his apartment and the safe containing his winnings empty. As they look into the victim's past spendings and charity, discovering he was trying to make up for the mistakes he made. Martha meanwhile has inherited a million dollars from her former fiancee Chet and wants to find some way to honor his memory.