Well, it's not a common ability in my world. You have to be able to use magic, because all these different dimensions are in constant motion, so sending something to one of them is kind of tricky. It's kind of like trying to hit a puppy by throwing a live bee at it. And opening a portal can be even more dangerous because you don't know what could come through the other side.

[It's not really the sort of thing Willow would recommend messing with for anyone who wasn't already an expert. And even then, she can't help but remember what happened in Deerington when a group of Sleepers tried to open portals to get back to the Waking World.]