'The Living Dead' by Brian Clemens (Based on a story by Anthony Marriott)

Steed finds a mine of information - Emma goes underground

In a remote village, a drunk sees the ghostly form of a miner rise up from his grave. Despite the state of the witness, Steed and Mrs. Peel arrive to investigate and meet the ghost-hunting representatives of two rival agencies - F.O.G. (Friends of Ghosts) and S.M.O.G. (Scientific Measurement of Ghosts). After the two agents encounter Kermit the Hermit, a derelict who hears noises from underground, the S.M.O.G. agent is killed and Mrs. Peel is kidnapped by a ghost. Steed investigates the mining disaster which killed thirty men five years ago, while Mrs. Peel wakes up to find herself in a secret city located directly under the village…

Patrick Macnee (John Steed), Diana Rigg (Emma Peel), Pamela Ann Davy (Mandy), Julian Glover (Masgard), Edward Underdown (Rupert), Howard Marion Crawford (Geoffrey), Jack Watson (Hopper), Jack Woolgar (Kermit), John Cater (Oliphont), Vernon Dobtcheff (Spencer), Alistair Williamson (Tom)

Directed by Gordon Flemyng
and Peter Duffell
Produced by Albert Fennell and Brian Clemens

TX:
UK: 18th February, 1967

Notes:
*Featuring John Steed and Mrs. Emma Peel

*”Mrs Peel, we’re needed”: While out driving, Mrs. Peel stops at a set of traffic lights, only to notice that one of the lights has the words ‘Mrs. Peel’ on it, and then in her mirror she sees Steed in the car behind. As the lights change the next one says ‘We're Needed!’

*The tag scene: Mrs. Peel finds that ghosts are inside Steed's car...