Val, the leader of the Menters, arrives on the Starcruiser Alpha 5. He comes with a shipment of Nuetron Guns. But the workers on board soon find out the Nuetron Guns aren't onboard, but in their place are Vervoid pods. They soon hatch and Vervoids run amok. The Doctor and Amy arrive, having dropped Karlel off on his home planet. But they soon discover not all is as it seems on the Vervoid-controlled Starcruiser Alpha 5.