I don’t want to give away too much, because some of the people I play with could find this (I don’t know if they use Lemmy but my nick is known and the details would be too unmistakable). But since they’re about to discover it anyways, the wonder does something, without charging the “proper” price for it, eventually they’ll start to lose control of it and it will start doing what it does to them. That should be subtle enough that even if my players find this they won’t know what’s coming but give you an idea. Hope that’s enough to satisfy your curiosity.