Sulu looked up from his tricorder and raised an eyebrow at Ianto, looking back over the river at the treeline. "Hear... what?" He paused, listening for any noise, but there didn't seem to be anything going on over on the other side of the river. That didn't mean he didn't believe Ianto, though - the man was cautious, but he knew what he was doing. If he heard something, it was unlikely to be the other man's imagination.

Then, the trees rustled again, the bushes by the riverside visibly shaking as something moved about them. Sulu paused, not as worried about it as Ianto was but still a bit cautious. "It might be one of the antelope-type things the ensigns have seen," he offered tentatively, because while it was the most likely explanation, saying it was just a deer was usually the first part of things going horribly wrong in these situations.