The Satanic Mass

Some foxing and general wear.
'The priest goes to the church at eleven o'clock at night, and so times his Mass that it shall end on the stroke of midnight. His server is a woman with whom he should have been intimate. Prayers are said backwards. A black three-cornered host and a chalice containing water are the elements of the offering. The water must be of polluted origin, preferably taken from a well wherein an unbaptized child has been drowned.'