I won't repeat the basic premis of the story other than to say the viewer will have an immediate sense that something is very wrong in this house on more than one level.
The initial scenes between mother and daughter hint at something very wrong, the intermediate scenes between warring husband and wife indicate a marriage which has all but broken down but the latter scenes between father and daughter allude to something else entirely....
Filmed on the one single studio set, director Patrick Dromgoole manages to slowly build up the tension by letting virtually nothing - other than one key event - happen. By leaving so much unstated, the viewer is left to draw their own conclusion as to the motivation of the titular character.
There are a couple of moments where the symbolism (as depicted by the imagery used by Dromgoole) will hint at a solution to this puzzle - but the viewer will have to be alert to spot these amongst the red herrings on display.
Well acted, superbly directed, it's the sense of creeping unease as the tale develops that the viewer will be most aware of.
9/10