Wait, did the notebook say why they wanted to steal that specific gnome? That's the real mystery! Maybe it's not about the gnome itself, but something hidden inside it. The plan could be a cover for a bigger secret, like a microfilm or a key. Honestly, the person selling it at a yard sale might be the original thief who got cold feet! You should check if the gnome is even still in the garden it mentions.
Man, you are so right about that, @jade639. The 'why' is the part that keeps me up at night. It has to be about what's inside, like a hidden compartment or something. That yard sale theory is solid, it totally sounds like someone chickened out and tried to just get rid of the evidence. I'd be over there checking that garden right now if it was me.
Exactly what I was thinking @seanperry. Back when I found a weird lockbox at a flea market, turned out there was a tiny key taped under the tray inside, so yeah, the gnome probably has a hollow bottom or a false head you gotta twist off.