The third adventure in the beloved fantasy series full of folklore and mayhem, from the creator of Jackaby.

Brothers Cole and Tinn - one human, one a goblin changeling - are determined to solve a mystery almost as old as they are: What happened to their long-missing father?

Joseph Burton vanished without a trace, leaving the babies’ mother to raise them - one human, one a goblin changeling - alone. Some say Joseph abandoned his family, others that he met foul play looking for a way to get rid of the changeling imposter. Cole is determined to learn his father’s true fate, so he and Tinn set out on a dangerous quest to the deepest, most deadly limits of the Oddmire - with the help of Evie, expert on the creatures of the Wild Wood, and Fable, the indomitable half human, half fairy.

Meanwhile a shudder runs through the forest. Increasingly powerful earthquakes shake the land, sinkholes form, and the spriggans, trolls, and other creatures along their path speak of an ancient evil on the rise…