The room behind the wall

The door opened but there was only space. Galaxies, stars and nebulae beyond the threshold of the door. 

She peaked her head inside and saw the door floating. Then with one step, she found a firm invisible surface outside the door. 

Carefully, without letting go of the door, she put both feet outside and suddenly the door closed as she held onto the doorknob. 

After the door closed it turned into an elevator door and the buttons cleared floating to the right of the door. 

She extended a hand to press one of them but before she could touch them, one of the buttons lit up and the door started to move downwards with her. 

Standing on this invisible surface it was inevitable to stop the falling sensation from the slow movement of the elevator. 

There was a ding sound and an unrecognizable symbol on top of the door, glowed the same colour as the button pressed. 

The doors opened into a hallway with white walls with a golden line with flowers and other designs on the wallpaper. The hallway was bright but there was only one door at the end of it. 

When she got there it didn't open. Confused, she walked from one end of the hall to the other but it didn't make sense. 

The floor was marvel tile and there was no way to hide a key. She knocked at the door but nothing happened.  

After a while of nothing happening, she started to walk back and forth touching the golden like on the wallpaper. 

She felt it once but didn't notice, then the second time she felt a part of the wall move as she passed her finger over it. Pressing that section like a button a section to the right of it popped out