What did Charley suspect when his friend Sam Weiner disappeared in the lesson the third level by jack finney?

Despite Charley's efforts to go to the third level, he was unable to find it again. He shared his experience with his wife, who got worried. He went back to his stamps. His friend Sam had disappeared and nobody knew where he was but Charley was certain that he had found the third level and gone there. Charley's description of the place had fascinated him and he had gone there in 1894.