The revelation that Jay Reese may be the "Big Bad" is a central plot point, intended to challenge Danny's lifelong perceptions of his mentor.
Their local guide betrays them, and in the ensuing chaos, they find the guide dead and Cleopatra missing again. [S1E11] Return of the Queen
Danny and Lexi later visit Simon Hardwick to use his recordings of the Brotherhood of Serapis to determine who actually has the sarcophagus. Critical Analysis Points The revelation that Jay Reese may be the