After one of Murdoc's go-to assassins agrees to hand over Murdoc to MacGyver in exchange for $10 million, the team finds itself protecting Murdoc from his former mentor, Nicholas Helman, who wants him dead. Also, Jack realizes he may still have feelings for Riley's mother, Diane.

When Nicholas Helman resurfaces to carry out a killing spree, the Phoenix is forced to get help from the one person who knows him best… his protégé, Murdoc.