Publisher's summary Edit
Two RAF fighter jets are on a training flight over North East Scotland when one of them is plucked from the air and promptly disappears. UNIT are called in, and the Doctor and Brigadier Lethbridge-Stewart are soon on the scene. They enlist the help of a local military officer - a young lieutenant by the name of Mike Yates.
The Doctor discovers a link to the recumbent stone circles that are plentiful in this part of Scotland. The stones are thousands of years old, and are soon revealed to hold a terrible secret. Then Mike Yates disappears, abducted by an alien race that has a grievance with humanity. Their intention is to harness the power of the stones in order to take their revenge. For the Doctor and the Brigadier, the race is now on to save their new friend Mike and the entire planet Earth.
An RAF fighter and its pilot disappear while on a training mission over the coast of Scotland. As the story told by the pilot's trainer John Morton is rather unusual, UNIT is called in, and the Third Doctor comes along for the ride (literally, as he brings his roadster Bessie with him). There they meet local army lieutenant Mike Yates, who is seconded to UNIT for the duration due to his knowledge of the area; it's the region in which he grew up. Corporal Macrae tells Mike that the pilot, Frank Parry, has been sighted near Inverurie. As the Doctor and Mike drive around the outskirts of Inverurie, they find Parry at the Easter Aquhorthies stone circle—but shortly thereafter, Parry reaches for the recumbent stone, and dies after putting his palms on it, apparently due to an energy discharge.
Stumped for leads, the Doctor chooses to take another plane and retrace the pilot's flight plan under similar circumstances; unknown to him, the Brigadier follows behind in a helicopter. The Brigadier's caution is rewarded; the Doctor sees many of the stone circles light up with power, and then a massive ball of power is released, streaking into space—and wrecking his jet in the process. He crashes safely into the ocean, and is rescued.
After some further investigation, Mike returns to one of the circles. He is immediately incapacitated, and is taken prisoner. His captors are Armidians from a planet named Tharos; only a few of them remain. In the course of painfully interrogating him, they reveal that they came to Earth a few thousand years earlier on a survey mission for natural resources; they were attacked by the local barbarians, and several of their number were killed. The remaining four Armidians were forced into stasis for the sake of their survival; but recent roadwork disturbed their stasis pods, awakening them. Now they want revenge for what they considered an act of war. It was they who built the stone circles, as data collection and transmission points; they have an affinity for igneous rock. They can harness the power of such rock using the Tharon stone that is native to their own world.
Meanwhile, the Doctor and the Brigadier are searching the area of Mike's disappearance. After spotting a boy called Davy Ross holding a flight helmet, they discover a dilapidated shed; but oddly, they feel a strong urge to ignore it. The Doctor determines that the shed has a perception barrier, which diverts attention; he pushes through it and opens the shed, and finds the now-gutted remains of the missing jet. Davy tells the Doctor and the Brigadier about the abandoned house inhabited by "beasties", which Davy can see due to his young mind. They take a squad of soldiers in, and find Mike being interrogated. They discover that the vengeful aliens now only wish to kill everyone on Earth; they have already sent a distress signal to their homeworld. However, the Doctor informs them that, sadly, their world has ceased to exist during their long sleep. Despite the Doctor's attempts at diplomacy, a battle erupts, and one of the Armidians is killed; their leader Garlin Munn teleports them out of the house, but Mike breaks free of the Armidians before he can come with them.
Before moving on, the Doctor receives a message via a telephone recording... and it appears to be from his future self. He learns that, despite the Brigadier's desire to end the encounter by force, the Doctor must somehow save the Tharon stone from destruction and give it to Professor Reynard of the Royal Society—and he must not tell the Brigadier ahead of time, as that would force his hand.
The Doctor determines that, given the affinity for rock, the teleport took the aliens to one of the circles. UNIT quickly locates them, and the Doctor and Yates race to the scene. In the end, the Doctor tells Yates to earth the stone using the wire fencing, returning its power to the Earth from which it was taken; the last of the Armidians die in the encounter.
Mike Yates is requested by the Brigadier to join UNIT full-time, and granted a promotion to Captain in the process.
to be added
- The story reveals how Mike Yates came to join UNIT, and also the circumstances behind his promotion to captain.
to be added