The Otherworldy Endeavors of Dante Bennett

Dante Bennett was just a regular 19 year old, trying to figure his way through his first year in Eastbrooke Community college when one night, as he is typing his midterm essay (or at least trying to)... a wooden door appears in the middle of his bedroom wall.
Yeah, you read that right.
Freaky right?
It started out pretty simple; you walk through the door...and instantly you're somewhere else.
I mean, that's the basis of most doors...but this one was different.
You're other places like, down the street to the old abandoned college library, Malloy's Bakery...other cities, states, and even countries.
Anyplace you concentrate on hard enough while walking through the door.
He never told anyone, and no one else seemed to be able to see it.
Actually, apart from the fact that his life had suddenly become somewhat of an episode of The Twilight zone, he started to enjoy the little adventures that he and the Door had.
Everything seemed to be working out fine until one day something happened that threw Dante for a complete loop.

Someone else came through the door.

It was a girl, and she told him that both of their Worlds were in grave danger.