We’re watching The Vow on Now TV at the moment, it’s about the NXIVM (nex-ium) pyramid scheme / sex cult.
The format is a little… uh art cinema for my tastes, particularly in terms of chronology, but it’s really interesting - particularly coming off a rewatch of Battlestar Galactica cos a couple of the cast are were, and continue to be, involved.
Also there’s absolutely loads of great first-hand footage, partly because of the nature of the organisation and their business, but also because one of the main guys who left was a documentary filmmaker who’d clearly been shooting stuff there for years.