Watch The Vow

'The Fall.' Finale. Keith leaves the U.S. and is spotted in Mexico. Later, the team faces a shocking development in the case.

'The Wound.' As the group prepares to testify to the FBI, they reflect on their beliefs regarding the SOP and JNESS curriculums.

'The Dossier.' Catherine meets with Frank Parlato to build a dossier of evidence for the New York Attorney General's office.

When they see no action by the authorities, Sarah, Mark, and Nippy contact additional news outlets to provoke outrage and pressure law enforcement to pay attention. Barbara Bouchey, a former board member and early defector, shares her insight into NXIVM and reflects on her time in Keith's inner circle.

Catherine believes her daughter is in danger and wants her to come home. But she and the former members are unable to get the attention of the authorities, so they approach the New York Times. While weighing the pros and cons of going on record, Mark reflects on his time at NXIVM.

Mark, Bonnie, Sarah and Nippy strategize with Catherine Oxenberg about how to get her daughter, India, out of DOS, even though she wants to stay. "Jane," a former member and India's close friend, describes the appeal of the organization and of DOS, and why she left it all behind.

Sarah confides to Mark about DOS, a secret women's group involving "masters" and "slaves." She struggles in her relationships with NXIVM, her husband Nippy, and her best friend. Nippy confronts the organization he's helped grow for 15 years. Sarah and Mark lament how many members they've recruited and question what to do next.

After seven years, Bonnie leaves Albany and NXIVM for Los Angeles to make sense of it all. She tries desperately to get through to Mark, who reassures her all is well. Meanwhile, Mark remains loyal to Keith and NXIVM, but a series of phone calls begin to sow doubt within him.

[HBO] HD. 'The Science of Joy.' Series premiere. Mark and Sarah, top former NXIVM leaders, describe the dream and mission of the organization.