As they began to walk down the street he kept his hand on the small of her back out of force of habit and also due to the fact that despite the fact that they probably weren't on an alien planet, it was still a weird place that gave him a bad feeling. He didn't know how far from home they were or how they'd gotten there, that was enough to put him on edge. The woman he'd talked to over his PDA had said that they couldn't leave, but he didn't see anything stopping them. He figured he couldn't take everything he heard from strangers at face value and it might be worth further investigation.
"Want to try an experiment?" He suggested, a teasing tone in his voice. She'd probably object to his use of the phrase, being her sciencey self and all.