This six-part drama follows the lives and loves of seven housemates. It starts in the present day when one of them has died and then goes back to the 1960s where they seem to be part of some kind of social experiment conducted by a young radical called Jack in a flat in London.
In his will the deceased has left the flat to his "former flatmates". Like my own brother he was dead for two weeks before he was found, so the flat needs some cleaning up. We see a group photo which shows the seven main characters as they were when they first moved in.
Jack wants to run a sort of island of egalitarianism where people do not have exclusive relationships - but he imposes his own rules, such as no one being allowed to sleep with anyone else for more than three nights.