Two young girls attempt to bring Christmas joy to a cranky old man so Santa will bring them puppies for their good deed.

Avery welcomes D.B. Russell to the team as they investigate a burglary/homicide committed by someone who hacked the home's security system remotely. Also, Avery considers moving to a new position within the hierarchy of the FBI, Krumitz is a witness in his sister's trial, Elijah deals with a delicate family situation and more is revealed about Nelson's and Raven's backgrounds.