Pope Benedict celebrating Mass in the Pauline Chapel in Rome.
At St. John's, the 5pm Mass is celebrated "ad Deum" ("towards the Lord" - also called "ad orientem", "towards the east"). In other words, in many parts of the Mass we join together with the priest in facing the risen Lord in one common direction of prayer. Popular Catholic blogger Father Z looks at what the Church's documents actually say about this style of Mass. Take a look!