Dinosaurs on a Spaceship Rory's father, Brian, unexpectedly joins the Doctor's gang of adventurers on a trip in the TARDIS to an ancient spacecraft on course for Earth. There, dinosaurs roam free and time is running out before the ship is destroyed in a deadly missile attack. A Town Called Mercy The Doctor discovers that the inhabitants of the remote town of Mercy, in America's Wild West, are unwittingly harbouring an alien war criminal, Kahler-Jek. The town is besieged by a cyborg gunslinger who threatens to kill everyone if Jex is not handed over to him. The Power of Three As Amy and Rory try to adjust to a normal life on Earth, away from the Doctor, millions of small black cubes appear from nowhere around the world. The Doctor soon arrives, joining forces once again with UNIT in an attempt to solve the mystery of the cubes.