Just as Lynn was explaining what oil was, magical barriers similar to each other rose above soaring towers, sealed factories, and the skies of the capital, blocking the falling firebomb rain.
In order to avoid surprise attacks by rebellious elements during fierce combat, which could burn down their granaries and armories, or even cause massive explosions, Lynn naturally had alchemists set up magical protections at key locations and arranged for many to be specifically tasked with guarding these places.
This was also why there were only ten thousand musketeers and a few hundred official wizards on the city walls, as the others were all assigned to auxiliary defense.
After seeing that the oil attacks were of little effect, some of the Griffin Knights lowered their altitude to claw and scratch the magical barriers with their talons—still quite effective in breaking magic, quickly scratching marks into the magical barriers...