Diamonds of Doom — Michael Dahl

Traveling by night, Zak Nine and Erro are following a shadowy figure until the mysterious stranger disappears into a cave. The boys decide to follow. Inside they find a maze filled with priceless gems, along with a rough band of escaped criminals. Things go from bad to worse when a squad of Alcatraz guards arrives on the scene. When the guards start shooting their laser blasters, suddenly nobody is safe! Will Zak and Erro escape the deadly storm of laser fire, or will they be trapped in the endless dark forever?