HBO Max released the trailer for the documentary series “Heaven’s Gate: The Cult of Cults,” directed by Clay Tweel (“Gleason”), set to premiere on Thursday, December 3.

The docuseries is a thorough examination of the infamous UFO cult through the eyes of its former members and loved ones. What started in 1975 with the disappearance of 20 people from a small town in Oregon, ended in 1997 with the largest suicide on US soil and changed the face of modern New Age religion forever.

The four-part docuseries uses never-before-seen footage and first-person accounts to explore the infamous UFO cult that shocked the nation with their out-of-this-world beliefs.

The first episode of “Heaven’s Gate: The Cult of Cults” will be available to stream for free on HBOMax.com/watch-free starting Friday, December 4 at 8 a.m. PT / 11 a.m. ET.