After another day full of adventure, Yakari and his faithful Mustang little lightning will save to sleep. But when Yakari wakes up in the morning, a small flash is not in the corral! Where did he disappear? Yakari has no idea that a small flash must undergo a lot of dangerous tests: to wade a wild river, find a way out of the labyrinth, or pass the fire test. He can handle them unscathed and return to Yakari?