The new door in your house

There is a new door in your house that was not there the day before. It's real, and you're the only one who can see it, too. What do you do? Do you open it? Where will it lead? And...did you hear a knock a few hours ago? No way. Can't be. *** Designed this to be a super open ended adventure for a random story, or a good starting place for people to start their own, specific Isekai. Just a simple hook that I bet a lot of people could really take off with. I like the idea because you can make return possible...or not! And who knows what crazy stuff the AI will come up with if you step through the door.