He didn't think she'd get it from that. He didn't expect anyone to see it but he couldn't miss it. He didn't react to her laughter except to press on, staring out into the night as he spoke. "That was the past. Here... you are the one they trust. You are the one who can protect them, who can pull them from... whatever threat comes. You are the one who is close to them. I did those things but that is done. I... will make my small contribution." Learn to hunt, learn to fight, talk on or the one or two subjects Sam seemed determined to limit him to. Watch Dean move on in all the ways Cas hoped he would have the chance to, all the ways he was never meant to be around to see. His gaze never left the dark beyond the glass.
"I don't know where I am going or when but you are theirs now," he shrugged. "What I think of it has no meaning to them. If I had a desire to change anything, I can't. They don't want you to go anywhere. I can't deny them." His jaw was tight, his fingers gripped the edge of the seat but he was far more resigned than angry.