That is one of the cagiest responses he's ever heard pass Serph's lips, which was in a way its own explanation. He's hiding something. Combined with knowing that the people here were also demons and at least one wore an atma mark (or what looked like one, he didn't recognize the type specifically), Serph's replies silence Heat entirely for a time.

On the surface it's both protecting these people, and lying through his teeth. It's not painting a pleasant picture, but it's also one he's not sure how to address. The possibilities were nearly limitless, from being under duress by one of these 'useless' people, to some extended form of Charm, to.. what else?

Maybe they're responsible for these wings.

Heat turns, as if that does settle the matter however temporarily, though it's certain it hasn't, fully intending to head further into the hospital. They don't need to hunt. "I do. I'm going. You can stay here or come find dinner, I don't care."