Lost in Nightwalk - Accidental Sorcerers, #5

The toughest challenge yet.Lord Darin is pursuing Sura. The Web is pursuing Bailar and Mik. Still, they continue teaching combat magic to sorcerers in Koyr and the Northern Reach. Training for conflict in the Goblin fastness, soldiers and mages start using Nightwalk, the vast maze under Ak'Koyr, for war games. Fleeing an assassination attempt, they find themselves lost. Now the problem isn't Lord Darin or The Web-it's getting out.
This is the fifth book in the "Accidental Sorcerers" series.