The thrilling sequel to the best-selling Bound.

Alex Caine is looking for direction and trying to build a new life with his recently acquired magical talents, and Kin girlfriend, Silhouette. He is recruited by a secret organisation to head off an impending doom, foretold by Seers as already somehow linked to his destiny.

Claude Darvill is desperately trying to get in touch with his father, Robert Hood. When the company, Black Diamond, reveals that Hood had gone missing after chasing Alex Caine, Darvill takes over control of Black Diamond and starts hunting Caine himself. Alex and his crew close in on three amateur mages in Britain's north, who think they have uncovered ancient magic that will reveal great powers. But they are caught in a vortex and pulled through to a strange lost city, isolated in the void.

Trapped in a place removed from everything they know, ruled by a hierarchy of monsters, Alex and his friends must find a way to escape Obsidian.