HBO’s The Vow got a lot of people talking about Keith Raniere and the NXIVM cult earlier this year, but if you’re looking for more fascinating material on cults, HBO Max has another non-fiction series coming next week. Heaven’s Gate: The Cult of Cults is a four-part documentary series about the infamous UFO cult Heaven’s Gate that started in 1974 and ended with a mass suicide pact in 1997. Directed by Clay Tweel (Gleason, Finders Keepers), the series features never-before-seen footage and first-person accounts including archival footage and interviews with ex-members and their families. Heaven’s Gate: The Cult of Cults arrives on HBO Max on Dec. 3rd; check out the trailer below and see what you think.