Yeah, and I haven't been able to figure out who did it either (so I figure I'll have to buy a new one...). Because that's not something you lend someone, and I didn't even know where the thing you use to remove it was, I found that a long time after the expansion pack disappeared. I was in the last temple when it happened too... :/

Maybe it means that if you destroy Majora's mask, most of the evil he's done is destroyed as well, not just the moon. But even so, it wouldn't change that the thief stole Kafei's mask, as that happened before Skullkid turned him into a child, right? So you would need to complete their quest and get the Sun's Mask back to have him show up at the ceremony. Makes sense. *nods*

Ooouch, that is a kick in the gut. Like "Here, you've just saved the world and things are mostly alright, but this guy's kid is still dead."