"He was your son, Scully." Explaining it is bleak, a kind of misery here never expected. Having to admit to Scully all the ways in which he'll fail, having to convince her that they really were failures, is cracking his heart open to a loss that's only grown deeper since he last looked at it head-on. He feels like he's staring into a lake, looking for a bottom that isn't there. "You carried him and raised him - and you had to make that call, knowing what it would cost you. I... wasn't as involved."