The biology of soft shores and estuaries Book

Sister Fidelma's 8th outing takes us into a world of jealousy, murder, revenge as well as ecclesiastical doubt in the staple of the murder mystery - the confined cast in a confined space. Unlike Christie, this is not a country house in the home counties but a 7th century pilgrimage from Ardmore to Santiago de Compostella, via navigational adventures in the Scilly Islands and Ushant. As well as the murder, there are pirates and treacherous seas; this has all the marks of a good adventure.

As with all of Tremayne's novels there is a solid historical basis and a sound underpinning of the tensions and rivalries between the Roman and Celtic churches, and in this case the deep seated tensions over asceticism and celibacy that become the most high profile of the differences. More prosaically, Fidelma is without her foil, Brother Eadulf - part of her reason for joining the pilgrimage is to review her feelings for Eadulf and her contradictory feelings over obligations to the law and the faith. These are resolved through the investigation of the ship board murders, and the tensions in the band of pilgrims centred on lust and jealousy.

Unlike many procedurals, this series does not rely on the enigmatic powers of the investigator as it does dogged pursuit - Tremayne's Brehon nun is more empiricist than enigmatic, with a powerful liberal modern outlook that is, paradoxically, entirely consistent with ancient Irish law. It is refreshing to see the accumulation of evidence, with just a little sharp insight, as the key player in detective fiction.

True to his genre, Tremayne has given us an engaging, enjoyable murder mystery. Thoroughly good fun.