Merlin would never betray Charlie because Charlie was the one who saved his life. In addition, Merlin felt that it was not the right time for Charlie to be reunited with the Ackers. Therefore, he could only play along and come up with a fake plan as long as it did not allow the Ackers to ultimately discover clues about Charlie. His mission would be completed, then.
Christian suddenly said again, “By the way, Merlin, have you ever thought about investigating the benefactor who saved your life?”