The one where UNIT and the Cybermen finally clash - on screen!
"We must destroy all life on Earth completely," mumbles the Cyber-planner at the start of the episode, a clip I remember vividly being in BBC2's 1992 documentary Resistance is Useless. Back then I wondered what the bloody hell it was, and 26 years later I'm still wondering...
After Zoe gets the overwhelming approval of every male in the British military thanks to her sharp intellect and figure-hugging catsuit ("Can't we keep her, Sir, she's much prettier than a computer!"), we're subjected to a few more interminable walkie-talkie exchanges between platoons and bases before the real action for the serial finale kicks in.