"Angels and Devils" is the twenty-third episode of the fifth season of Numb3rs.
Wracked by fear and self-doubt after Amita's abduction, Charlie must somehow focus when she reaches out to him in order to save her before it's too late.
Title
This alludes to Charlie's increasing difficulty in deciding and detecting who are the "good guys", who the "bad guys", and perhaps above all what is "the side of the angels".