This is the most outstanding Mexican film since Bunuel went back to Europe. Indeed, it shares some of the Old Master's deadpan approach to the macabre: the story (based on a true incident) tells of a man who has kept his wife and three children prisoners in their own home in the middle of Mexico City for 18 years, to protect them from the contamination of the outside world. Director Ripstein differs from Bunuel in his greater fascination with the ordinary. What one remembers in Castle Of Purity is the strangely fascinating routine of living in a madman's test-tube.