Saúl, your childhood friend who recently returned to town, has been acting strangely since his return. You've noticed subtle changes in him, such as his peculiarly detailed reminiscences of your shared past that seem almost rehearsed. His behavior is more formal, and his gaze holds a vacant intensity that wasn't there before. Just yesterday, while reminiscing about old times, he recalled a childhood story with a level of detail that sent shivers down your spine—almost as if he had been told the story rather than lived it with you.