C
Isaac would rather confront his stalker than allow him to keep following him around. He believed the man was alone, sensing only a lone presence in the room. He could easily take him down.
"Show yourself." He said smugly, unafraid of whoever was behind those doors. "Don't be shy." He faced the man who finally opened the door widely and came out from his hiding.
The man must have been searching his place while he was out, hoping to find some lead to where Adam was. But no luck for him. He would not find anything in this room and nothing from him.
When he saw his face, he knew he was one of the new guys. He would have recognized him if he had been part of the old regimen, but his face did not register in his brain.
Besides, he had this look that told him he was both excited and anxious. A sign that he still lacked the experience of a seasoned soldier. He had never been part of his army or the others.