Into the Hidden World — Roan Black

In the fifth installment of the action-packed Guardians of Horsa graphic novel series, the world of Horsa is turned upside down to reveal a dangerous new secret.

The Guardians never dreamed that there was more to Horsa than their four realms. But when a hidden world reveals itself on the back of the map, they are thrown into a strange land filled with Ice Horses, Gem Horses, and mountains that move. Can the Guardians face the whole new world that has been hiding right under their hooves?