Flik Silverpen's Guide to the Great Goblin Flight

From the introduction:

The Big Boom Crew, a group of bomb-obsessed goblins, have stumbled across a powerful levitating stone. They plan to take flight, vanquish a vicious beast, and create a dazzling and destructive fireworks show.

But the enterprising wizard Roshab, has other plans. He desperately wants the stone, the key ingredient in crafting a mass-produced spellbook. Roshab is offering an enticing reward for the stone, drawing the attention of ghoulish mercenaries, enterprising apprentices, and the adventurers.