"The details of the life of the time seem very authentic"
The story is set in Oxford in 1434 at the time of the Corpus Christi festival. A troupe of itinerant players has arrived to play “Isaac and Abraham”. By happy chance they meet up with a local worthy who offers them bed and board if they will also entertain his family and guests. Joliffe is one of the members of the troupe and he finds himself investigating the death of a stranger whose body is found outside the barn where the players are lodging. He also discovers a link between his playmaster, Basset, and their benefactor, Master Penteney.
This story revolves around the dissident group of Christians known as Lollards who had been active in Oxford some time previously. Another death occurs when Master Fairfield, the Downs Syndrome heir to some good lands, dies in the midst of the festivities. Joliffe applies a mind trained in logic at the university to solve the mysteries and the troupe move on to greater things.