It is 72 AD, and most of Britain is under Roman domination. At Aquae Sulis, a place of pilgrimage and healing, hot waters gush ceaselessly from the earth. Since ancient times the waters have been associated with the supernatural, and are under the protection of the Celtic Goddess Sul. The Romans have renamed her Sulis Minerva, and have tamed the steaming waters to form a complex of public baths.

A statue of the hated Emperor Claudius is being erected in the precincts of the Temple of Sulis Minerva. The centurion Decius Brutus, a Celt, is ordered to return to his home town to protect the statue and prevent trouble. But the local people, led by his proud father and his fiery daughter, Megan, are threatening rebellion...

Meanwhile, Megan's twin sister Ethne is torn between her destiny as Oracle of Sul, and her love for Lucius, who is caught up in his own quest for spiritual enlightenment, with the help of the Orphic priest Demosthenes.

Twenty miles away, on Glastonia Island, a small Christian community struggles to establish a new religion in a hostile land, away from Roman persecution.

Cults from Rome, Greece, Egypt and Judaea vie with the native Celtic beliefs and form a rich backdrop to the human dramas that unfold.

The Waters of Sul is set in a time of transition and adjustment, when beliefs are questioned and loyalties are tested. Love and hate, conflict and reconciliation, troubled romance and an uneasy traffic with the supernatural all feature in this brilliantly conceived novel from a masterful storyteller.