4T. The Invisible Enemy

TRANSMISSION DETAILS:

458. Part One                      01.10.77   6.20pm - 6.45pm   8.6M/40th/---
459. Part Two                      08.10.77   6.05pm - 6.30pm   7.3M/55th/---
460. Part Three                    15.10.77   6.10pm - 6.35pm   7.5M/50th/60%
461. Part Four                     22.10.77   6.10pm - 6.35pm   8.3M/50th/60%

     Part One                Thu   13.07.78   7.00pm - 7.25pm   4.9M/60th
     Part Two                      20.07.78   7.00pm - 7.25pm   5.5M/76th
     Part Three                    27.07.78   7.00pm - 7.25pm   5.1M/81st
     Part Four                     03.08.78   7.00pm - 7.25pm   6.8M/35th

SUPERVISOR LOWE: Michael Sheard; CAPTAIN SAFRAN: Brian Grellis; MEEKER: Edmund Pegge (1); SILVEY: Jay Neill (1); CREWMAN: Anthony Rowlands (1); PROFESSOR MARIUS: Frederick Jaeger (2-4); OPTHALMOLOGIST: Jim McManus (2-4); DR PARSONS: Roy Herrick (2-3); MARIUS'S NURSE: Elizabeth Norman (2-3); DR CRUICKSHANK: Roderick Smith (2-3); DR HEDGES: Kenneth Waller (2); RECEPTION NURSE: Nell Curran (2); NUCLEUS: John Scott Martin (3-4); NUCLEUS VOICE: John Leeson (3-4); A MEDIC: Pat Gorman (3-4). UNCREDITED: CREWMEN: Harry Fielder (1), Stuart Myers (1); COMPUTER VOICE: Anthony Rowlands (1); BI-AL MEMBERS: Leslie Bates, Alan Clements, Margot Gordon, Derek Hunt, Kenneth Sedd, Cy Town

STORY:

A spacecraft en route to the Titan base is infected by a virus, and the same virus - the Swarm - also attacks the TARDIS. The Doctor is infected by the Nucleus of the Swarm. Landing at the Titan Base the Doctor and Leela are threatened by the crew. The Doctor and Leela manmage to get away to a hospital for the Doctor - the Bi-Al Foundation.

Professor Marius is able to clone the Doctor and Leela, minaturise them, and inject them into the real Doctor. The hope is that they will be able to find the infection and destroy it.

The Swarm nucleus manages to get out and is enlarged to human size. It arranges for transport back to the Titan base where breeding tanks have been prepared for it.

The now cured Doctor, along with the help of Professor Marius's mobile computer K-9, manages to set a trap which will blow up the breeding tanks. As a parting gift Professor Marius leaves K-9 in the care of the Doctor.

STUDIOS: Television Centre Studio 6

WORKING TITLES: The Enemy Within, The Invisible Invader

NOTES: K-9 does not appear in Part One

NOVELISATION: The Invisible Enemy Terrance Dicks