The Tower Besieged (Paperback) (ISBN-13: 9781763755321)

In service of the Tower, a hidden organisation, Zack and his friends fight monsters, travel to magical realms and protect the world, unbeknownst to most.

But Zack's final year of high school also has its own demands.

His dream girl remains just out of reach, and his magic is not yet strong enough to heal his dying grandmother.

After copies of a strange ritual emerge, Zack and his friends are assigned to a secret mission to uncover the plot of renegade mages and find out whether the trail leads them back to the Tower.

The mission will test the teens, their burgeoning magical abilities, their resolve and their friendships.

With the future of the Tower, and the world at large, on the line, Zack will discover if he is up to the task set before him.

Most of all, he will have to decide what he's willing to sacrifice to save the world...