Two 20 year old twins descend into a life of murder and exploitation in this 1970 horror thriller from director alan gibson arriving at a london house incestuous twins julian martin potter and jackie judy geeson waste no time murdering the resident housekeeper before embarking on a wild night on the town eventually ending up at a swinging houseboat party its not long before the pair find themselves the centre of attraction for a group of sordid underworld characters