Doctor Who The Stones Of Blood Part 1

Tracking the third segment of the Key to Time, the Fourth Doctor, Romana, and K9 arrive in modern-day Cornwall. They meet Professor Emilia Rumford and her friend Vivien Fay, studying the "Nine Travellers"--standing stones in Boscombe Moor. Their work is disrupted by a Druidic sect that worships the Cailleach, the Druidic goddess of war and magic, led by de Vries. De Vries and the sect are hostile to the newcomers, but the Doctor later finds the sect killed by mobile stones similar to those of the Nine Travellers and determines the stones must be alien beings that feed on blood. He and Emilia find evidence that suggests Vivien is older than she looks. Meanwhile, Romana catches Vivien awakening more stones with blood, and Vivien uses a device to send her to a spacecraft in hyperspace. When the Doctor and Emilia arrive, Vivien tells them that Romana will be safe before disappearing herself. The Doctor recognises the stones as Ogri, a life form from the planet Ogros.

The Doctor constructs a projector to cross into hyperspace, leaving Emilia and K9 to guard it. On the spacecraft, the Doctor determines it is a prison ship, and inadvertently releases two floating globes called Megara that serve as justice machines. They accuse the Doctor of breaking a seal on the ship and prepare to put him on trial. Elsewhere, Vivien finds the Doctor's presence, and returns to Earth, awakening one of the Ogri and damages the Doctor's projector, but sparing Emilia's life as a friend. She and the Ogri return to the craft to attend the Doctor's trial. K9 guides Emilia in repairing the projector, allowing them to bring back Romana, along with an Ogri. They are pursued by the Ogri, leading them back to Vivien's cottage. There, Romana discovers an alien device that proves Vivien is not human. They lure the Ogri back to the projector, and she and the Ogri return to the spacecraft.

On the ship, the Doctor learns the Megara are seeking a criminal known as Cessair, who had stolen the Great Seal of the planet Diplos, which grants its bearer great powers. The Doctor suspects Vivien is Cessair, and attempts to force the Megara to question her, but their law prevents such intervention. Having decided the Doctor's guilt, they fire an energy weapon at him, but at the last moment, the Doctor drags Vivien into the shot. The Megara immediately stop their attack and scan Vivien to see if she is unharmed, but instead discover that she is Cessair. Romana arrives with the additional evidence, and the Megara pass judgement on her. They return her to Earth and transform her into a standing stone in the moor, but not before the Doctor recovers the Great Seal which she wore. The Megara are about to pass judgment on the Doctor when they're forced to return to their ship and depart to Diplos. The Doctor had set the controls of the ship before leaving, and he affirms the Great Seal is the third segment of the Key, and he, Romana, and K9 thank Emilia for her assistance before they leave in the TARDIS. She smiles as she now has a new stone in the circle to study.