Opal Crown - Book Five of the Seven Stones of Power

Alaric has returned from Castalia with the Topaz stone to heal Alena, if he can. A task that is vital to his journey, but he may already be too late.
The Alliance must march on Castalia where a Dark Knight controls the largest army in the Seven Kingdoms. The walls of Castalia have never been breached and victory will be Bern's biggest challenge to date.
It is time for the wizards to leave their island and join the army if the Alliance is going to have any chance of winning the final battle. It is going to take all of Alaric's skills to convince them.