Box Not Box: Writing Prompt

This box was a box. Until it was a portal into a civilization 300 miles underground, which it was until it was a secret bed. And then it became a wheel-free race car.

Things are better when they turn into other things. 

Today, your character has to use a common, everyday thing and make it extraordinary. That mug? Now it's a pool for a new race of very, very small creatures, just discovered on his keyboard. That pillow? She's pulled out the stuffing so she can re-create a snowy day in her living room.

Have fun!