Costigan might have flinched right then if he wasn't paying so much attention to his exterior, showing some things but not letting on just how distressed he was to Dick. Maybe the warden would pick up on something being off, but not what it was, not with all the training he'd had and all the time he'd spent with Costello.

"Two of my friends left, a lot of shit's gone down, and there's no use thinkin' about it when I can't do anything to change it." He replied honestly, though he omitted Mal entirely.