From the moment young Egan arrives in Instep, he senses the spell cast over the villagers by the Megrimum - the mysterious something that lurks on the mist-wreathed peak of Kneeknock Rise. Everyone shudders in horror - delicious horror - whenever the Megrimum's unearthly wail floats down to the village. Before long, Egan is climbing the Rise to find a practical explanation for those wails.