This idea came to me after reading Last Cask of Amontillado by Edgar Allen Poe. (Neither of them are related, just the revenge story got the gears spinning)

It had been years since he'd done anything to break my heart, that I knew of-of course. I feel though, as if he's hiding something. He's been gone for almost a week now, and I guess I must make due to entertain myself or find something to do. Maybe I could find something with some interest to me. After all, what could he be hiding from me?