The scene is London, in 1399. It is the last year of the fourteenth century, and there is talk of an apocalypse.
Richard II is on the throne, yet strange signs and portents are troubling the latter part of his reign.
By the side of the River Fleet in Clerkenwell the people are restless, disenchanted with the church and their King.
The streets of London are rife with rumour, heresy, espionage and murder and at the centre of the confusion is the nun, Sister Clarice, who has been vouchsafed visions of the future.
Is she a genuine prophet, or the tool of earthly powers?
This is a story of adventure and suspense set in the late medieval world.
As in many of Peter Ackroyd's novels the distant past is no longer a foreign country but something alarmingly close and authentic.
As one critic has put it, 'he is our age's greatest London imagination'.