Gregor was about to ask what was wrong - he could see her shivering, so unlike her! - when the same feeling enters his gut. He drops what he's holding, almost doubling over. He'd never felt anything like this before... He couldn't even think to describe it.

Fear, mixed with... With... Don't go in, don't step further, don't, go back, go back, gobackgobackgobackgoback-

He clutched his chest and closed his eyes. "Such... awful magic... Must... we must go back..."