What is Bear involved with in Great Wexly

It is clear by chapter 36 that Bear has some clandestine connection in the town of Great Wexly. When he arrives with Crispin he asks Widow Daventry for his regular room at the inn, which turns out to have a secret hiding place behind the wall. This raises the question as to why exactly Bear needs a hiding place.
In chapters 40 and 41 we discover just what Bear is involved with. He leaves Crispin to meet with John Ball. This priest is the only historical character to appear in the book. John Ball was one of the leaders of the Peasant Revolt of 1381. In the story, Crispin overhears Bear and John Ball discussing plans and ideas of how to bring reform to England. It is clear that Bear is one of the conspirators of the peasant uprising. Bear has important information for John Ball, but Crispin is unable to hear what it is.
Later, in chapter 48 we discover that Bear has been captured by soldiers. Crispin believes it is because of his involvement in the secret meeting with John Ball and the other leaders of the revolt. Indeed, John Ball and his fellow conspirators worry that Bear will betray them if tortured. It is clear that Bear has crucial knowledge of the conspiracy.