Classic Doctor Who

Seabase 4 is on alert. A strange craft is approaching but the crew has been infiltrated by the enemy, so Commander Vorshak's solutions are stopped at every turn.

The Silurians and Sea Devils send the Myrka in as a spearhead to the invasion of the Seabase, whilst Nilson and Doctor Solow work to bring the entire Bloc down.

As Vorshak's crew are cut down one by one by Sauvix's Sea Devil Warriors, the Doctor is running out of ways to broker a peace between mammal and reptile.

Lethal hexachromite gas is used against the invaders and the Doctor is despondent that no one wants to find another way to avoid so much death.

Teacher Jane Hampden is increasingly frustrated by the war games being played around the village, but the Doctor is more alarmed to find a boy transported from the 17th century.

The Malus's influence is asserting itself all over Little Hodcombe, and the war games take an unpleasant turn. The Doctor's best defence is in the TARDIS - but the Malus is inside.

Captain Revere is the latest person to be sucked beneath the ground on Frontios, leaving the young Plantagenet to run the colony. The Doctor's TARDIS has also been destroyed.

Trying to discover why Frontios is being attacked from both above and below, the Doctor faces the malevolent Tractators while revolution brews in the colony.

Turlough's race memories of the Frontios threaten to overwhelm him as the Doctor finally convinces Brazen that the threat from underground is very real.

The Doctor manipulates the Gravis into restoring the TARDIS, but still has to find a way to break the Tractators' hold over Frontios before they wipe out all life on the surface.

Davros is held captive aboard a prison in space but the Daleks launch a rescue attempt.

As survivors of the prison station fight the invaders, Dalek agents on Earth take steps to protect the time corridor being used by the Doctor's friends.

On the planet Sarn, the truth about the god Logar is being searched for, while on Earth Peri wants a break from her stepfather. But the Master has other plans for everyone.

Kamelion has taken the TARDIS to Sarn and is trying to locate his master, while the Doctor explores the mystery of the Misos Triangle - much to Turlough's consternation.

Logar is angry and the volcano shakes with his displeasure - according to Timanov, who demands sacrifices to appease his god. Peri discovers the Master's whereabouts.

The Doctor is forced to take drastic measures against Kamelion and the Master to stop Sarn being completely destroyed by the numismaton gas that has been released.

Gunrunners are on Androzani Minor, supplying the rebellious android-builder Sharez Jek with munitions to help his attempts to return to power. But not everyone is happy about that.

Military captive Salateen tells Peri and the Doctor they are dying from spectrox tomaemia and the only cure is the milk of the queen bat, who sleeps deep below the caverns.

As Morgus continues to plot his political future on Androzani Major, Sharez Jek insanely believes Peri will fall in love with him. The Doctor is caught by the gunrunners.

Morgus is ruined, exposed as the one funding Jek's gunrunners, and Jek himself goes on a murderous rampage. Although dying from spectrox tomaemia the Doctor saves Peri.

The mysterious Professor Edgeworth has kidnapped twin human child genii, Romulus and Remus, and Hugo Lang holds the new Doctor responsible for the destruction of his spaceship.

On Jaconda, Mestor's cruel domination over the planet's population continues while on Titan Three, the Doctor seems to have been blown up in a booby-trapped building.

Mestor claims that all he wants is for the Sylvest twins to help him repopulate his home planet but the Doctor knows there's more to this than meets the eye.

Mestor's true plan is revealed and the Doctor's old Gallifreyan friend Azmael comes to the realisation that he has been corrupted long enough by the Gastropod leader.