Runes Limitations

He just barely managed to land between two bicycles, but he still landed on hard asphalt.
He tried to bend his knees to absorb the shock of impact, but he heard an unpleasant
noise from his ankle. He had only jumped from the second story and it did not feel
broken, but he had hurt his ankle a bit all the same.
He heard the roar of flames absorbing oxygen coming from above.

“!?”
Kamijou scrambled along the ground, kicking bicycles over as he did so, but nothing
more happened.
“?”
Kamijou looked up with a puzzled look.
Still making the roaring noise, Innocentius was clinging to the second story railing and
staring at Kamijou who was on the ground. It was almost like there was an invisible wall
keeping it from following Kamijou.
Apparently, the runes had only been placed on the dorm building. Kamijou had
managed to escape Stiyl’s flames by leaving the building.

- Toaru Majutsu no Index Volume 1, Chapter 1 Part 7