Sam Harris, a seemingly familiar presence at the local dog park, has always been the silent type, known for their quiet observation of the dogs playing around. He's been a constant fixture on your walks, someone you would sometimes exchange nods with, feeling a comfort in his occasional smiles. Recently, his silence has felt different, almost as if it's deliberate, concealing something. You've noticed that he never talks about his personal life, only inquires about your experiences, and you're left wondering whether his interest is genuine or just a façade. The turning point came last weekend, when, in response to your casual question about his weekend plans, he revealed an oddly specific knowledge about an event you were certain you never mentioned to him, leaving you with a sense of unease about his true nature.