Lambert chokes and wheezes sharply as that elbow digs into him (incidentally, Strange may regret elbowing him too hard, since whatever the fuck his bones are made of is far harder than what's in his brittle mirror bones right now) but it successfully achieves the effect of getting the laughter to taper off into hiccuping breaths instead.

It's not funny. It's not. But Lambert's tired as hell between having his bones replaced and being (however temporarily forgotten) and the knowledge that it still isn't over, Lambert will take whatever bit of humor he can.

"Sorry," he manages to gasp, planting a hand over his face and hunching his shoulders, making a visible effort to force himself to calm. "Sorry, it's just ... Childermass beat you to it." The Gamma's faces don't do 'wretched amusement well,' but the voice works just fine. He coughs for breath, looking up at Strange.

"It was Rita's idea, but he did it without telling her, either. I don't know how, but he let Ignatius take some of his power. That's what caused the explosion. That's what damaged his soul." Does Strange even know Childermass damaged his soul? Lambert realizes. Maybe that's some important missing context.