Impossible Book One: The Darkness Returns

Soren couldn't believe it, had Eglantine actually turned to the Pure One's side? The Pure Ones return, full force and with a devious plan to destroy the Guardians. The Guardians will need all the help they can get, but when Eglantine switches sides, all of Soren's hopes are lost and he must do the impossible to defeat his own sister, but can he?