Beware My Brethren is a 1972 British horror drama film. It features Ann Todd, Patrick Magee, Tony Beckley, Percy Herbert, Suzanna Leigh, David Lodge, and Ronald Allen. Led by a sinister minister, a controlling religious sect called the Brethren has taken control of widow Birdy Wemys, sending her unstable son, Kenny, into a spiralling descent into madness and murder. No woman is safe when Kenny's religious mania overpowers him and leads to a rampage of carnage and chaos!