Anarchy in Royston Vasey - S2-E5
Visible crew/equipment: When Hilary Briss and Samuel are sitting in Hilary's living room, Hilary says, "Are you alright Samuel? You look a bit nervous." When Samuel says, "Of course I'm nervous." there is a microphone at the top of the screen, above his head.
Anarchy in Royston Vasey - S2-E5
Visible crew/equipment: When Tubbs is urinating into the petrol tank, as Steve Pemberton moves away, you see a hand that was holding the can of 'urine' move out of sight behind the car.
Chosen answer: The members of the League refuse to admit what it's actually supposed to be, but have stated that it's possible to work it out from clues in the series. Human flesh seems like the most likely candidate, probably supplied by Edward and Tubbs from their general butchery of any non-local who sets foot in the place. Another theory is that cocaine is involved in some way as its effects seem to match most of the things that the special stuff is supposed to cause. So, combining the two, and why not, the "special stuff" is non-local human meat sausages impregnated with cocaine.
Tailkinker ★