The Dragon Hunters' Secret

How can you kill a dragon?

For the initiation into their tribe dwarves must complete a journey to the land of their ancestors. Here they must kill a dragon and return with its heart. The precious oil extracted from the heart is the rare commodity that sustains their impoverished tribe.

Dragons are huge, indestructible, breathe fire, and are said to be magical. How can their tiny weapons prevail? They will learn the astounding answer. And, they will also learn there are other perils than mere dragons.