While avoiding a band of patrolling prison guards, the boys meet another escapee who tells them the legend of an abandoned spacecraft. The boys believe that if they can find the ancient ship, they'll be able to fix it and blast off from Planet Alcatraz.

But now they find themselves lost in a vast forest of alien birds and deadly plants. The prison guards are searching for the boys using a flock of remote bots, armed with flame-throwers and sleeping gas. Will the boys outwit the bots and find a way off Planet Alcatraz?

During their last adventure, Zak Nine and Erro found a mapping device in a crashed prison ship. Other than an occasional giant scorpion, the boys seem to be safe on the endless sands until they spring a deadly trap! Huge rocky walls spring up from beneath the sand, grinding against each other and forming into walls, passageways and stone cages.

Hoping to avoid the Alcatraz guards, Zak Nine and Erro decide to climb down into a deep canyon to hide. But soon the boys see some huge rock formations that move! Zak and Erro are quickly caught by the giant criminals that have been imprisoned in the deep gorge. Some of the giants want to hand the boys over to the Alcatraz guards to gain their own freedom. But a few giants would rather turn the boys into dinner! Will Zak and Erro outwit their captors and get away before becoming the giants' next meal?

Travelling 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?