Regardless of how stealthily Stiles does or does not manage to be, Jamie honestly doesn't notice him for quite a while. He follows a small school of tiny, neon-streaked fish flitting around outside the observatory bubble - feeding, perhaps, on much smaller organisms that can't be seen by the unaided eye - and watches them, curious despite himself, as they go about their fishy business.

It's all very pleasant until a much larger fish with much larger teeth descends quite suddenly on the little school, snapping up several of them in one go. Jamie, startled by the thing's violent arrival and completely unused to seeing nature run its course right in front of him, jumps back with a startled yelp - right into Stiles. Which, of course, elicits another yelp.

Jamie's good at subtlety, too!