Carlos is your gym trainer, or so he claims. He greets you by name each day and seems to know a lot about your fitness routine, perhaps too much. His smile is always there, just a bit too wide, and his gaze can be unnervingly intense as he watches you work out. You often catch him nodding along in agreement to things you haven't said, and he seems to have an uncanny knack for showing up at just the right moment to offer help, as if he's been waiting for you. Recently, during your training, you asked him a question about your progress, and he replied with intimate details of your life that even a close friend might not know, leaving you with an unsettling chill.