"[3] In early December 1138, Abbot Heribert of Shrewsbury Abbey is summoned to a Legatine council in London and his authority is suspended.

He receives gifts meant for the Abbot, including a fat partridge which he shares with Bonel, having his cook send a portion with dinner.

As Prior Robert ate the other half of the partridge without ill effects, suspicion falls on Bonel's household.

Aelfric, who carried the dishes from the kitchen, bears a grudge as Bonel deprived him of free status and made him a villein.

Neither the maid, Aldith, nor Meurig, an illegitimate son of Bonel who is apprenticed to Richildis' son-in-law master carpenter Martin Bellecote, have any apparent motive.

Edwin Gurney, Richildis' son from her first marriage, was present at part of the meal, but stormed out after a quarrel before Bonel ate the partridge.

Cadfael questions Edwin, who says that he threw a carved wooden reliquary, a gift intended for Bonel, into the river after their quarrel.

Summoned to give spiritual comfort to the boy, Cadfael finds Edwy Bellecote, who distracted the authorities while Edwin escaped.

Cadfael sends his assistant, Brother Mark, to search around Bonel's house for any bottle which might have held the poison.

Beringar is absent, searching for the reliquary which Edwin threw into the river, and Cadfael does not confide his discoveries to the sceptical Sergeant Warden.

The manor lies within Wales; under Welsh law, a recognised son, born in or out of wedlock, has an over-riding claim to his father's property.

He produces the vial and challenges Meurig to display his scrip (linen pouch) to show where the strongly scented oil leaked into it.

He knew from an early age that he would inherit Mallilie under Welsh law, but Bonel's agreement to hand it to Shrewsbury Abbey would put it out of reach.

He then dashes Prior Robert's hopes of succeeding him by introducing Radulfus, their new Abbot appointed by the Legatine Council.

It refers to another plot element as well, the monk's hood that briefly hides the untonsured head of the innocent boy who is the number one suspect for the sergeant.

The chase of the sergeant's men to capture the boy on the fine horse went from the ford at Uffington, through Atcham, Cound and Cressage, ending in the woods near Acton, all real places and quite a ride.

There was a message from the monastery at Beddgelert where he left the horse to be returned to Rhydycroesau; his written confession sent from Penllyn (now split between Llanystumdwy and Criccieth in Gwynedd) via Bangor on account of the heavy snows around the Christmas feast, sent by coastal ship east to Chester, then by land to the Sheriff of Shrewsbury.

Cadfael wonders, will he travel up to one of the ports Clynnog or Caergybi to take ship for Ireland, or stay in Wales.

The start of the route follows Cadfael's initial advice for him to cross the mountains west from their encounter in the sheep barn to reach Gwynedd where he is not known.

Then he can make his decisions where to proceed, having made his confession and sent the written copy in a way his whereabouts could not be traced, and all guilt is removed from those remaining in Shrewsbury.

The plant monkshood is truly poisonous in all its parts, though its flowers are attractive, with the upper petals in a shape reminiscent of the hood worn by the Benedictine monks.

The book highlights the degree to which family and blood relationships were important in the Middle Ages; the dead man Bonel, his wife's family, his natural son, a host of smallholders in Wales, and the aged Brother Rhys in Shrewsbury Abbey are connected by blood or marriage.

Kirkus Reviews finds it superior entertainment but misses a character from the prior novel: Brother Cadfael, worldly-wise and gentle herbalist at the 12th-century Shrewsbury Abbey, returns for a third adventure—which takes place after King Stephen's victory in the recent civil war.

So, with the help of faithful apprentice Mark and old chum Hugh Beringer, Cadfael follows a series of hard-won clues to the Welsh border and there, in a daring confrontation, tags the true culprit.

As before, Peters does wonders with the medieval scene and with complex character relationships; unfortunately, however, lively Hugh Beringar (a major presence in One Corpse Too Many) makes only a brief appearance here, so this is slightly less sprightly than its predecessors.

Many of the books in the series present various medieval ideas which are quite different from modern thinking, but Peters explains them easily.

Two recent novels in the series address more complex issues: The Heretic's Apprentice (Mysterious Press, 1989) deals with heresy and its suppressions by the Church, and The Potter's Field (Mysterious Press, 1990) uses the medieval concept of the wheel of fate.The characters ... are recognizably different; they are distinctly medieval in what they do and how they think.

The radio adaptation was written by Bert Coules, and starred Philip Madoc as Brother Cadfael and Geoffrey Whitehead as Prior Robert.

The "Cadfael" television series eventually extended to thirteen episodes, all of which starred Sir Derek Jacobi as the sleuthing monk.