Dima was not expecting anyone else to approach. He startles a bit at the sight of the almost entirely white person, but then calms down. No, this one is solid. He's speaking to him. This one is real.

"I...I think so." He pauses to swallow and catch his breath. He has a prominent Russian accent--clearly foreign, but not so thick as to be hard to understand. "I just need to catch my breath. I--I thought I saw something." Which should really be in the present tense, but he doesn't want to sound like a lunatic.