How good is your cat's sense of smell?
I was a little amazed. Toby gets some treats when I go to my room to go to bed. Once in a while I'll place them somewhere when he's not watching where he has never seen them before (not to hide them, just to put them down while I get ready and do some other stuff. When I get back they're gone and I'm surprised he even knew they were there.
Or we'll be playing chase, where I run out of a room and he'll wait and come after me. I'll hide behind a chair or a door that I've never been behind before and he'll just walk right up to where I'm hiding.
It that his sense of smell that's leading him to me?