Despite being awake, Theo was still very much under a blanket of sleep and confusion at being out of his expected surroundings, wandless to boot, and so he flinched when Ernie's hand rested close to him despite the fact that he'd been taught better than that; he'd beat himself up about it later. He was still tense though and absolutely ready to flee or fight in an instant if he had to, not quite certain he was safe just yet.
He'd stopped tracking over Ernie though as he scanned the room, which was good. He wasn't seeing his friend as a threat. "How did I get to your flat?" he asked, confused because he was sure he remembered going to bed in his own place. He could feel the irregular lurches of his heart in his chest, slowing down but beating out of time in a way that was uncomfortable but familiar ever since a spate of Cruciatus when he'd been thirteen had left him arrhythmic. "Have you seen my wand?" He sat back a little, not so much calming down but clamping down on his panic already, shutting down more than anything else into some semblance of control.