In the world of Asgard, living among Odin, Thor and Loki are the Valkyries of legend.

They are Norse goddesses who reap the fallen souls from human battlefields and have the power to cause death with just one touch.

At the end of The Runaway, Freya and the Valkyries are about to leave the human world when they learn that the Frost Giants, Fire Giants and Dark Searchers have united to declare war on the Realms.

Bitfrost, the legendary rainbow bridge linking the human world to Asgard, has been closed.

With their only entry back to Asgard barred, how can the Valkyries get back to fight to protect their homeland?

Loki claims he knows another, secret route but can they trust him? And even if they found a way - is there anything they can do to stop the war?As the War of the Realms spills over into Earth, Freya and the Valkyries must find a way to save not just the Norse world but the human world as well.

With everything at stake, can Freya become the Hero she was destined to be?'Kate O'Hearn serves up a winning mix of modern adventure and classic fantasy.' Rick Riordan, author of Percy Jackson