On a peaceful walk through the woods, virtuous sister Maria (Pezet) happens upon Satan in human form (Rocha) and is soon possessed by his malevolent spell.

Maria now finds herself compelled to seduce her fellow nuns, rape a local boy and murder her Mother Superior! It's a normal day at the nunnery.

Will Christ liberate her from Lucifer's evil hold before the whole convent goes to Hell in a handbasket?

Based in part on The Monk (released the same year and scripted by surrealist Luis Buñuel), this allegorical nunsense is redeemed by a good straight performance from lead Pezet and generally beautiful cinematography throughout.

Some spirited dashes of gooey gore help to keep things greased.

Overall, a much classier effort than you might expect.