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  • title card: white all caps text reading 'THE BIG THINKER' superimposed on a croner of the lab, showing a maniframe computer rack and cooling pipe
  • Dr Kearns plays cards, unaware that his mathematical ability will not help him in a rigged game
  • Dr Clemens is found dead in one of the ducts, Dr Kearns peers in from the far end
  • Cathy and Steed hold Broster and Clarissa at gunpoint after disarming them
  • Farrow sees his own name on the printout identifying the killer
  • Steed's bag is packed for a mission in Tel Aviv and tagged with his Carruthers alias

Series 2 - Episode 12
The Big Thinker

Teleplay by Martin Woodhouse
Directed by Kim Mills

Production Schedule

Episode 15 (41)
Production Number : 3514
VTR/ABC/2217 & 2217 A + B
Teddington Studio 1

Wednesday 12th December 1962

Camera rehearsal 10.00-12.30
Lunch break 12.30-13.30
Camera rehearsal 13.30-18.00
Supper break 18.00-19.00
Line Up and Make Up 19.00-19.30
Camera rehearsal 19.30-20.00
(VTR/ABC/2217-A + B)
Camera rehearsal 20.30-21.00


  • 2217A - Brensall's death - 0:18-2:00
  • 2217B - Cathy & Steed meet in the Amusement Arcade - 9:00-11:43

Thursday 13th December 1962

Camera rehearsal 10.00-12.30
Lunch break 12.30-13.30
Camera rehearsal 13.30-15.30
Tea break, Line-up,
Normal scan, Make-up
Dress rehearsal 16.15-17.30
Notes 17.30-18.00
Line Up 18.00-18.30
VTR 18.30-19.30

Running time

Expected: 51'25"
Actual running time with bumpers: 51'46"

The bumpers between the acts are generally 10 seconds from fade in to the "End of Act" bumper to the end of audio before the commercial, a 10 second still without audio, then cut to the next act bumper. This would play with the theme for around 10 seconds. Accordingly, with the episodes being in 3 acts, the running time of the action is approximately a minute less than listed above, minus the opening and closing credits (normally 0'16", with a 2" fade, and anywhere from 0'41" to 1'20", hard cut or 1" fade or mix, respectively).


London 15t December 1962
Sydney 13th January 1964
Melbourne 6th August 1964


Cameras: 4 Pedestals
Sound: 4 booms; 1 slung Ops. Room.
Telecine: ABC symbol and Caption Scanner only.
VTR: 2 Inserts


Victim Killer Method
Dr Brensell Dr Farrow gassed and frozen
Dr Clemens Dr Farrow electrocuted
Dr Farrow Dr Farrow electrocuted
Click a name to see the face


Marque/type Plate


  1. 4:14 - Kearns' calculations:
    (4 x 3162)2 = 175... 8919... 2978... 304... oh, and so on and so forth.
    apparently, contrary to what he says, it appears neither Kearns nor Plato can add up as the answer is 159539531776.
    3259 / 263 = 12.39163498098 recurring - no, 8.. 2... [1 2 9] (spots Cathy) hello, hello, what have we here?
    (It's actually 12.391634980986).
  2. 9:28 - When Cathy says that Hurst is in a panic and wants "MI5, the Navy, whoever" Steed replies, "You he can have, I'm off to the Middle East tonight." Is this admission that the organisation is MI5?
  3. At the end of their discussion in the amusement arcade, Cathy says, "You're staying out of it?" and Steed replies, "Yep, you go right ahead, Mata Hari. Just send me a postcard."
  4. Pinball scores:
    Cathy: 1970 Steed: 1280 and 1891 (well, it goes up a bit more, but we don't see the final score)
  5. 24:28 - the camera takes a second to focus on Cathy when she turns on the light.
  6. 28:15 - the camera dips briefly as if it collided with something
  7. 38:42 (37:33) - One of those boom mikes sneaks into shot again while Steed is helping Cathy apprehend Broster and Clarissa.
  8. 39:15 - Steed identifies himself to the police as "Carruthers"
  9. 50:30 - instructions for caring for Sheba: half pound of meat, some seaweed powder, a special teaspoonful of cod liver oil and a long walk daily.
Times are from the re-mastered 2009 Optimum Releasing DVD set, any times in brackets are from the previously released DVD sets which had frames with interference or banding deleted, resulting in shorter running times.

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