Description - taken from here

There is no more inventive—or scary—miniature in Catherine's prayer book than this full-page depiction of hell. A gaping lion's mouth opens its batlike lips tipped with talons; inside is another, red-hot maw. Demons cast damned souls into this terrifying entrance to the furnace of hell, above which rises the castle of death decorated with skulls. Burning towers heat caldrons into which mutilated souls are pitched. A third mouth forms the domed roof. At the bottom crouches a green demon whose mouth sprouts scrolls inscribed with the Seven Deadly Sins. In the smaller miniature, the holy water and incense offered by the priest to a corpse seem like scant protection for the potential horrors depicted in the facing image.

Office of the Dead

The Office of the Dead was in the back of every Book of Hours the way death itself was always at the back of the medieval mind. While the other prayers in a Book of Hours are quasi-liturgical (reflecting but not equaling official Church practice), the Office of the Dead is identical to that found in the service books used by the Church's ordained.

It was assumed that most people's entry into heaven would be delayed by a detour (lasting, potentially, thousands of years) in purgatory, the fires of which cleansed the soul of unforgiven sin. Praying the Office of the Dead for one's deceased friends or relatives—who could not pray for themselves—was one of the more efficacious means of reducing for them the fiery price of paradise. Recited at funerals, the Office of the Dead was also ideally prayed every day.

The three Hours of the Office (Vespers, Matins, and Lauds) consist of psalms plus a series of moving readings from the Old Testament Book of Job. The trials endured by Job become an allegory for one's time on earth—and in purgatory. The voice of Job, crying for pity and mercy, becomes the voice of the dead.