(And hope, I like your thinking, but you need to get the hell out of here.)
"The hell is wrong? I've never seen you this scared. I'm not going to die; worst case, I'll call Hannah to get me out of here," Ethan muttered, moving forward.
(Then do it now. Tell her to get you out of here immediately. I'm serious—have you ever seen me this serious?)
"Then tell me why. Do you know what's in this cave?"
(I don't, but I know it's something powerful, and you're not ready to face it yet.)
"Still, I'm going in. Besides, calling Hannah in this fog is dangerous. When I'm somewhere the fog hasn't reached, then I'll call her. But for now, I'll keep moving forward."
[Spatial Awareness]
With this, Ethan was able to sense his surroundings, but he couldn't detect any of the others who had come with him.
However, he could sense an empty room with a source of Mana.