How to combine Entities?

[Vipes]

Not exactly. It depends on what you're trying to do. Many things would require that to be one only mesh.

A broken doorway leads you to a hallway full of bookshelves; stacked to the brim with books. You walk down, the candles behind you blow out as the first two bookshelves fall behind you. You start to run, they fall faster, almost seemingly like they want to crush you out of your very existence. At the end of the hall there is salvation, a door. You open the door and rush inside as the last bookshelf falls.