Klaus and Bill
Bill knew trauma when he saw it. He'd been a child living in a post-war world, seen the scars and the loss left behind. Battles fought and won but never forgotten and Klaus had that far away look in his eyes, like he wasn't really even seeing him. There had been hints about it, about what he'd been through and what he'd lost, but Bill hadn't ever seen him like this.
A laser hit Bill's shielding charm and he felt the impact a little, but recovered to drop the shield and fire off a few more charms and push the aliens back away from them.
If he apparated he was worried he'd go and leave part of him behind, especially because he was in such a panic. "We're going to get out," Bill assured him as he brought up the shield again and dropped down onto his knees. "I'm not about to leave without you, love," Bill soothed him gently.