The Fearsome Lava (2)

One of the master teachers tried to pass through the light barrier as he had done before, but as if ramming into a wall of concrete steel, he was knocked back by a powerful might.

"This…" The eyes of the master teacher narrowed in disbelief. "How are we to leave now?"

He wasn't the only who reacted in such a manner. There were also several other master teachers who rushed up to the seal to try it too, and upon realizing that they were unable to pass through it as well, their faces paled in horror.

Passing through the seven-colored light barrier from before had been extremely easy for them. It was just like diving into water, not impeding them at all. However, the current white, misty barrier before them was like a thick block of steel in their path; no matter how they rammed at it, it just wouldn't budge.