The first series follows John Armstrong who attempts to find his girlfriend Lioba Fielding who is dead in the real world but alive in Planet B.

As he travels between various worlds he becomes entangled in an array of strange scenarios, teleporting from each adventure to the next with his companion Medley, a "rogue avatar" who has no human controller.

All the while, John and Medley are being watched by a dog-like antivirus programme called Cerberus who, along with the Planet B Corporation, considers the rogues to be a computer virus that need to be wiped out.

In the second season, Lioba is on the run from Planet B and travels the virtual world with computer games expert Kip Berenger after they are attacked by Cerberus.

The series was created by Sam Hoyle, Jessica Dromgoole and Matthew Broughton with James Robinson.

[7] Lioba commits suicide in the real world by throwing herself off a cliff, to the distress and horror of her boyfriend John Armstrong.

[5][8] John discovers that Medley is in fact a "Rogue avatar" - an advanced form of computer virus that can think for itself.

John and Medley help to cure Lioba, and they unite in order to prevent more rogues from being destroyed.

A new character called Kip Berenger (Joseph Cohen-Cole) is introduced, a computer games expert who followed the uprising and is a fan of Lioba.

The end of the series sees Kip crying at the realisation that he has committed murder and that he is now master of Cerberus.

He claims it is to provide a new service, Planet B Platinum, but in reality the goal is to kill all the rogues in the old site.

While in an area of Planet B that simulates the Black Forest, Pip encounters a voice which turns out to be Medley.

Cerberus helps Kip and Medley, having learned that he too is a rogue and had false memories implanted by the corporation to make him believe that he had a life outside Planet B.

Planet B was the largest ever original drama commission for BBC Radio 7, with the first series being ten episodes long.

"[17] On 6 March 2009 Scott Matthewman from The Stage wrote: "I am shame-faced, in that I missed this intense drama serial off last week's preview.

"[18] Ian Dunn from One Giant Leap also wrote positively: "The series has been amazingly gripping.

He also commented: "One intriguing thing about the series so far is that some of the scenarios have been rather adult for a show broadcast at 6pm.