 Denise Van OutenProfessor Polonium | Professor Polonium |
 Steven KynmanSam / Elvis / Charlie / Norman (voice) | Sam / Elvis / Charlie / Norman (voice) |
| JJohn HaslerArnold / James (voice) | Arnold / James (voice) |
 Colin McFarlaneMalcolm Williams / Map-Screen 700 | Malcolm Williams / Map-Screen 700 |
 David CarlingStation Officer Steele / Mike Flood / Tom Thomas / Trevor Evans (voice) | Station Officer Steele / Mike Flood / Tom Thomas / Trevor Evans (voice) |
 Kerry ShaleDoctor Crumpton (voice) | Doctor Crumpton (voice) |
 Sasha BeharRose Revani (voice) | Rose Revani (voice) |
 Alex LoweJoe Sparkes (voice) | Joe Sparkes (voice) |
| TTegwen TuckerPenny / Sarah / Bronwyn / Mrs. Chen / Teleprinter / Map-Screen 700 (voice) | Penny / Sarah / Bronwyn / Mrs. Chen / Teleprinter / Map-Screen 700 (voice) |
| HHarriet KershawEllie / Bella / Scoop Dooley (voice) | Ellie / Bella / Scoop Dooley (voice) |
 Su DouglasDilys / Mandy / Helen (voice) | Dilys / Mandy / Helen (voice) |
 Nigel WhitmeyMoose Roberts (voice) | Moose Roberts (voice) |
| GGary AndrewsGareth Griffiths (voice) | Gareth Griffiths (voice) |
