British space scientists are experimenting with breaking through the Van Allen belts – two belts of highly radioactive particles 509,000 miles up in the earth’s atmosphere.
As the series opens, American astronaut Mike Sklorski (Frank Fenter) is returning to Earth, having successfully traversed the belts and performed a single orbit of the planet.
His shuttle returns safely with the astronaut in fine health but it is discovered that the cameras and tape recorders inside the capsule had stopped for nineteen seconds prior to re-entry.
Sir Robert Nailer (William Dexter), the British Head of Space Research, is keen to discover the cause and ascertain any side effects Sklorski may be experiencing.
Less than an hour after the capsule is opened, the astronaut dies – with no apparent medical reason for his death.
Nailer becomes even more concerned when Doctor Weatherfield (Felix Deebank) – the first man to enter the space capsule when it was opened – disappears from his hotel after a terrible nightmare in which he had “absorbed” the mind of the dead astronaut.
Meanwhile, a new giant radio telescope is receiving an unintelligible signal from an unknown source.
With Weatherfield still missing, the astronaut, Sklorski, is seen alive, leading Sir Robert Nailer to believe that Sklorski and Weatherfield have become one body with one personality.
Elsewhere in Britain, other pairs of men are encountering the same phenomenon – one is killed, one goes missing. The number of victims doubles each time while the amount of time between events reduces by half. It appears the earth is under some form of intelligent attack from two alien forces – the Jotus and the Nebula.
This six-part science-fiction series from the BBC was highly innovative at the time and compellingly addictive, keeping viewers guessing to the end whether it was radiation contamination or an alien encounter.
Sir Robert Nailer
William Dexter Dr Alan Tullis
Ray Roberts Lady Nailer
June Tobin Mrs Stone
Joan Frank Anderson
Frederick Treves Bruton
Michael Browning Pam
Laura Graham Van Heusen
Keith Anderson General Nant
Paul Bacon Royston
Ian Clark Enders
John Collin Det. Supt. Allison
Fred Ferris Kemble
Robert Fyfe Jeff Murray
Raymond Mason Janet Nailer
Susan Purdie Mathews
Frank Shelley Mrs Anderson
Iris Baker Det. Chief Supt. Stroud
George Street Radio Announcer
John Graham
