Looking at the Gate of Heaven, Roy found that the light of the magic formation was still bright, meaning that there was still some time before it closed.
The space that Heaven was in was a Purgatory Space, a kind of subspace. Roy could only enter here after cracking the encryption in the main world. But if the Gate of Heaven closed, and he wanted to return to the main world from Heaven, it would be very troublesome.
Why?
From the space magic Roy learned, this was probably because the subspace was much less stable than the main world space.
In many cases, the difference between a main world and an inner world depended on the stability of the space they were in. Purgatory Spaces were a kind of space bubble attached to a main world space, so their stability was naturally much worse. After all, these kinds of space bubbles would sometimes drift away from the main world and sometimes burst, just like real soap bubbles.
