The Best Episodes Written By Johnny Byrne

The automated Earth space probe Voyager One is approaching the Moon. With the radioactive exhaust from its engine certain to extinguish all life on Moonbase, the Alphans try to gain control and shut down the drive. Help comes when the probe's designer is found living on Alpha under an assumed name. However, Voyager is being followed by alien ships seeking revenge.

After an encounter with a space-time anomaly, the Alphans find their Moon back in the Solar System on a course to re-enter Earth orbit. The celebration ends when it becomes apparent Earth is an inhospitable wasteland. The mystery deepens when they discover a duplicate Moon already in orbit and a duplicate Moonbase Alpha lying empty and deserted.

The wandering Moon suddenly changes course and comes to a halt in the vicinity of a dead world. As Alpha's power fails, the only hope for survival is to evacuate to the planet, which was ravaged by a nuclear war in the distant past. Searching for answers, a team is sent to the surface, where they discover the shocking truth of the origin of Mankind.

An Eagle is sent onto the surface of the planet Psychon, which has titanium, needed for repairs to the Alpha Base. It fails to return and is used by Psychon scientist Mentor as a bait with which to entice other members of the Alphan crew onto the planet. Mentor is building a computer but it will be fuelled by the living brains of humans, and he has his eye on those of the Alphan crew. Fortunately his daughter, the shape-shifting Maya, does not share her father's views and is on the side of the Alphans.

Hard-bitten police inspector Walters has a murder on his hands that he can't crack. The prime suspect is George Stamford, who was alone in a locked room with the dead man when he was shot - but he is admitting nothing, and there is no evidence against him.

An auditor finds out that Oliver is defrauding his firm. But when he demands some hush money, he discovers a nasty surprise.

With an anti-matter being trying to enter the universe through the Doctor, risking the destruction of everything, there is only one clear course of action for the High Council of Time Lords to take: execute the Doctor. Meanwhile, Tegan arrives in Amsterdam and hears about what's become of her cousin from his unscathed friend.

Something seemed amiss about the Doctor's execution, so the Castellan has Commander Maxil discreetly but fully look it. Meanwhile, as the Doctor meets the anti-matter being inside the Time Lord Matrix, Tegan and her cousin's friend run afoul of a bird-like alien back on Earth.

The planet Traken. The Traken union is a society living in perfect harmony, watched over by the powerful but benign Keeper. But now the Keeper is dying, and he senses a great evil within his protectorate. Can the Doctor help him discover the secret of the Melkur?

On Gallifrey, someone on the high council is perpetrating a treasonous act - transmitting the Doctor's bio-extract from the space/time matrix to an anti-matter being. On Earth, two English lads spend their last night in Amsterdam sleeping in a crypt where they're attacked by an alien creature under the same anti-matter being's control.

While exploring an asteroid, the Alphans injure an alien trapped within. Bringing him to Alpha, they discover his wounds have completely healed. The indestructible Balor is a scientist whose people had discovered the secret of immortality. Balor is a psychopath, offering a drastic solution to his people's apathy; now freed of the eternal prison, he plans to spend eternity practicing the art of pain and torture, with the Alphans as his subjects.

The arrival of the Alphans on another planet seems to cause a change in its atmosphere, setting off pollution and poisoning of the water. They meet Zoran, the sole survivor of the last exploratory force, who tells them that the planet is controlled by an immortal being - with whom Koenig must parley if he and his crew are to leave the planet alive.

The Dorcons -the most powerful race in the galaxy -demand that the Alphans hand Maya over to them. Koenig refuses, until Moonbase Alpha is savagely attacked and invaded! Then, having let them take Maya he makes a desperate attempt to save her....

Tremas claims consular privilege to protect the Doctor and Adric from execution, though it binds his fate to theirs if they're found guilty of murder. Melkur strengthens his hold over Kassia while Seron decides to have rapport with The Keeper to learn truth, and Adric finds evidence of another TARDIS in the area.

With Tremas falling under suspicion, due to his association with the Doctor, a new Keeper Nominate is named. Now, with everything in place, Melkur has only a short wait before his full malevolence can unfold.

With the merciless Melkur in control of The Source, the Doctor and his allies have only a slim chance of deposing him, which also puts the peace of the Traken Union in severe jeopardy.

Just as the Doctor gains a tentative trust from the humans, a Silurian battle cruiser approaches. The Doctor warns Commander Vorsha to hold his fire and find out what they want, but is the level-headed commander one who'll listen?

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

With Silurians in control of the base, Icthar reveals his plan for a final solution to Earth's human problem, which presents the Doctor a great moral dilemma.

A lush Earth-type planet holds the promise of a new home for the people of Moonbase Alpha. When the reconnaissance Eagle returns, it carries an unexpected passenger: Helena's husband, who died five years ago. The mysterious Lee Russell tells the Alphans that death awaits them on the new planet. The Alphans ignore his warning and unknowingly descend into a world of antimatter.

Earth's ocean floor, 2084. With two superpowers poised on the brink of a devastating photonic war, a missile base comes under attack from the reptilian Sea Devils and Silurians, intent on eradicating the upstart human race and reclaiming the planet…

The body of Anton Zoref is invaded by an unknown life force. The man soon manifests an uncontrollable ability to absorb energy. As the Alphans struggle to understand this mysterious force, Zoref's need becomes insatiable. Driven by instinct, he makes his way to the greatest source of energy on Alpha: the Nuclear Generating Plant.

Encountering a derelict spaceship, the Alphans respond to an automated distress signal. On board, they discover what remains of the once-great civilisation of Daria: an elite group which maintains control of the ship and a tribe which has descended into savagery. The Alphans are appalled when they discover what measures the Darians have taken to survive.

Dan Mateo, hoping to unlock the secret of communication with plants, unleashes a killing force from the depths of his own mind. This macabre spectre seeks vengeance for Mateo's horrible death—which has not yet occurred. Bridging the span between science and the supernatural, the Alphans hope to break the cycle and exorcise the ghost without killing the man.