He pursues Kass

"Wait!" Theron called out to the boy who called himself Kass, but Kass kept walking.
Theron began to chase after Kass, and Kass, noticing his pursuer give chase, began to run.
"Please stop" Theron called but Kass ignored him and took evasive actions in an attempt to lose Theron. Kass had no idea who his pursuer was or who he thought he was, but he did know there was an unsettling gap in his own memories.
'Kass' was not his real name, of course. He had picked it up, many years ago.

For all Kass knew, his pursuer could be telling the truth, but he was too scared to care about the truth. Finally Kass stopped, out of breath. He gasped for air as he slouched over and spoke to himself, “Finally I lost him.”
Out of no where, a hand was placed on his shoulder, and he flinched upright. Theron, the owner of the hand spoke, “Please, listen. I don’t mean you any harm, but I know who you are and I only want to talk.”