"We're going to worry about that later. You need to calm down." Harry was sure Sirius was handling whatever the Auror felt he needed to handle.. and that was good enough for him. "That's what you need to worry about right now." He pushed his hand back down onto his good shoulder, still holding him down.. just in case. He knew that whatever calm Remus might be feeling would wear, soon, if he was allowed to sit and think. But he couldn't think of much to do that would distract him from something so drastic.
"When I was thirteen, on the train to Hogwarts, I ended up sitting in the same cabin as you. You rode the Express to school... I hadn't ever heard of a teacher doing that before. We had no idea who you were. But on the way there, the train stopped and a bunch of Dementors boarded.. one came into our cabin, and I.. well, I don't respond to them well. At all. I passed out, and when I woke up, you gave me chocolate. It really.. really helped." Maybe if he could just keep talking, he could keep Remus calm. Tell him about what a great person he'd grow up to be.