... It uses its serious theme to give extra force to a tale that already has plenty of flair as a pure and simple spine-chiller.

A thriller whose mandate is to startle its audience with surface-level shocks while simultaneously subverting expectations in a deeper way, dropping us out of our comfort zone toward some sunken place.

The prize asset is Moss, of course, a seven-octave actor equally happy with micro-emotion and going very big indeed.

Elizabeth Moss gives us a performance that is likely one of her best.