Doctor Who: Darkstar Academy & Day of the Cockroach
Mark Morris and Steve Lyons Audio Book

Darkstar Academy: When the TARDIS is buffeted by "time slippage," the Doctor experiences a terrible vision of the end of everything. Tracking the source of the disruption, he takes Rory and Amy to what appears to be an English public school in the 1950s. But as the friends are about to discover, there are some very unusual things about Darkstar Academy. For a start the prefects carry guns, and then there is the strange force-field that surrounds the perimeter. Not to mention the foot-long, crab-like creatures with spiny, armored bodies...When the Doctor learns the truth about the Academy, he also discovers that the whole place is in terrible danger. But with a swarm of carnivorous creatures on the loose, what can he, Amy, and Rory do to help prevent a terrible disaster? Day of the Cockroach: The TARDIS materializes in a pitch-dark tunnel, where the Doctor, Amy, and Rory stumble on the dead body of a soldier. Questioned by his superior officer, Colonel Bowe, they learn that they're inside a British nuclear bunker, in the middle of an atomic war-in 1982. Amy and Rory weren't even born then, but they know the bomb didn't drop that year, and so does the Doctor. The friends also know they had nothing to do with the death of Sergeant Trott-so who, or what, was the killer? And why does the Doctor's psychic paper not work on the Colonel? The Doctor, Amy, and Rory soon learn that something else is lurking in the shadows. Something deadly...