This documentary by acclaimed director Vanessa Engle tells the extraordinary story of a strange cult, which came to light in 2013 when a sensational news story broke about three women emerging from a small flat in Brixton in south London after decades in captivity. Tracing the group back to its roots in the 1970s, the film describes how its leader Aravindan Balakrishnan, a student of Indian origin, believed in an international communist revolution and created a tiny political sect that followed the teachings of China's Chairman Mao. The film features exclusive interviews with two of the women who escaped - Aisha Wahab, a 72-year-old Malaysian woman who was part of Balakrishnan's group for 40 years, and Katy Morgan-Davies, Balakrishnan's daughter, who was born and raised in captivity. The film documents how this left-wing collective evolved into a bizarre pseudo-religious cult, where members were controlled, threatened and brainwashed so that they were too terrified to leave.