'Undermind' is new to me. Sounds fascinating: 'an alien force, that was never identified by name or location, sought to establish a foothold in Britain by undermining society and morale through the use of high frequency signals with the power to brainwash the susceptible to commit subversive acts'.
I agree it sounds great, an interesting Quatermass-style premise written by several Dr Who scriptwriters - what's not to like? Apparently the swines at ABC (not the BBC this time) wiped all but 3 episode.
I might be able to get those three episodes. I'll report back.