Book 2 of the Omnifex Chronicles series

Hundreds of metres below the city of London, thirteen year old Montgomery Vane tries to forget about his horrible new school on the Surface and master the powers he used to defeat his evil Aunt Payton. But figuring out how to control his magic is a lot harder than he hoped.

And there’s no time to lose! A terrifying new threat is surging through the Underworld. If Montgomery is going to help save his friends from the fearsome soldiers of Atlantis, he needs to learn fast – even if it means forging the most unlikely of alliances.