The Man In Black (1950)

After her husband's untimely death, Bertha Clavering (Betty Ann Davies) became an extremely wealthy widow, determined to keep the estate for herself and her daughter, Janice (Sheila Burrell). Returning home after a lengthy stay abroad, step-daughter Joan (Hazel Penwarden), rightful heiress to the Clavering wealth, unwittingly enters a house of terror and intimidation as Bertha and Janice conspire to drive her insane, going to any lengths to achieve their goal... including murder.

Also stars Anthony Horwood and Sid James.

Based on the BBC radio series.