The Children's Film Unit, formed by ex-Avengers writer Colin Finbow, produced films by children, for children. Finbow taught kids every aspect of film production, both behind and in front of the camera. Channel 4 showed some of the best CFU films, and they were very dark indeed.

Daemon (1985) concerned schoolboy Nick Foster, who, after moving to a new house and school, starts to develop inexplicable sores, hears strange voices and (the 80s!) his home computer displays uncanny messages. Is Nick depressed... or haunted?

Then there was 1984's Dark Enemy; the young survivors of an apocalypse set out from their idyllic valley to find a new leader for their tribe, but when the cause of the Elder's extinction is revealed, things will never be the same again...

Doombeach (1989) is nothing less than 'Edge of Darkness' for kids. After 13 year-old Gavin's mate is hospitalised after swimming in the ocean, he suspects the local power plant of pumping waste into the water (I've cut away from the surreal, bleaker than bleak ending here)...

1990's 'Survivors' is a favourite of mine. Ian (Rockliffe's Babies) Hogg is a teacher who takes his class on a survival holiday to a remote island, has a full nervous breakdown, then starts hunting them down like animals...

Here's the kicker: Channel 4 showed the CFU films in the early morning/afternoon as part of their Xmas and New Year schedules. A sort of Mirror Universe version of the squeaky-clean Children's Film Foundation, the CFU is a long-forgotten but brilliant corner of British film.

All of these films, and a few more, are available on YouTube, thanks to the brilliant 'treffynnon19' channel. Check 'em out, and God bless Colin Finbow!