Horns of nimon

The Skonnan empire is already dying away, but many still long for conquest. Nimon arrives at Skonnos, promising in exchange for a tribute to restore former greatness in exchange for a series of offerings from their leader Soldid in the form of a group of young slaves from the planet Anet and several crystals of a gemist. But the ship with the last batch of stolen breaks down in space, and the first pilot dies.

TARDIS is in a disassembled state for modifications. It materializes too close to an artificial black hole, so the Doctor expands the TARDIS force field to the hatch of the Connes ship and transfers to it with Romana. On board, he notices a gemmetist crystals and a hold with young people. The co-pilot leads the travelers at gunpoint to the bridge, Roman repairs the ship with the help of a gimetist, and the Doctor goes to the TARDIS for tools. On board, he learns of the fall of the Schonnann Empire.

The pilot starts the ship and the TARDIS is in danger of getting lost in space, but the Doctor manages to get to Skonnos. A ship with captives and Romana arrives there too. The co-pilot lies to the Soldier that he repaired the ship himself, but he, along with the captives and Romana with crystals, is sent to the maze of Nimon. The Doctor goes there too. In the complex, Nimon kills the pilot, but he is distracted by the Doctor, who saves Roman, Set and Tek.

Nimon turns on his car and a luminous tunnel appears. A capsule appears to travel between black holes, from which two nimons emerge. They announce that the planet Krinot is dying, and the nemons must continue the Great Journey of Life to Skonnos. The doctor accidentally sends the capsule along with Romana, but before he returns everything to its place, the Soldier arrives and breaks the control panel.

On Crinote, Romana meets an old man named Sizom, who helped the nemons arrive in their world. He found that an ash crystal inserted in a staff of nimons helps to stun them. He gives Roman one crystal and helps her escape, but dies himself.

The doctor repairs the transport and returns to Roman. She passes the crystal to Seth, who stuns Soldid, takes his staff and cuts down the arrived nemon. Seth kills Soldid, who tried to blow up the complex with everyone, K-9 leads everyone out, and the whole building explodes.

Seth and Theca take the ship with the captives from Skonnos, Krinot explodes, and the threat of the Nimons no longer exists.

• This is the last episode (not counting the Shad episode), where David Brirlie voiced the K-9. At the beginning of the next season, John Leeson returned to this role.
• Apart from the Shada series, this is the last series for the producer of the series Graham Williams, who was replaced at the beginning of next season by John Nathan-Turner, who remained until the end of the classic series, and composer Dudley Simpson, who worked with the series from the beginning of the second season (it was replaced by Peter Howell )
• The series mentions that Romana had a sonic screwdriver, but she lost it.
• The series is based in part on the myth of Theseus and the Minotaur , which the Doctor comments on at the end.