Easter egg: On Disc 6, go to the Bonus Features section. Scroll down to the second option, and the light in the cabin on the right hand corner of the screen goes on. Click on it and you'll find a surprise.
Easter egg: On disc four of series 3, go into the scene selection, go to the last page, highlight "keep looking" and press "up." You know have the whole easter egg that was part of the story.
Easter egg: In the special features on Disc 6, go down to "Inside Quantico and the Criminal Mind", and press right on your control; this should highlight the image of a gun. Select it to view a short tour of the CM offices and set with Edward Allen Bernero's assistant Rosalie.