The price of a freedom is very expensive. People sometimes give up his life for status as a free man. Though obviously they were outnumbered and outgunned, but that fact does not make them retreat. Whatever happens, Rochester Castle must keep them maintained.
The year was 1215. British nobles who rebelled forced King John (Paul Giamatti) who they are loathe to acknowledge their freedom as human beings. King John's Magna Carta to be willing to admit. Unfortunately, the Magna Carta claiming means eliminating some of the rights of King John, and it seems this despot did not want it to happen. Initially King John was willing but several months later he reneged on his promise.
King John then collect the mercenaries to subdue the rebellious nobles of this. The only thing that is still a barrier is the Castle of Rochester. The castle is controlled by the rebels and they would not surrender to death. King John had done all the way but the rebels remained unyielding. They are willing to die for independence. Only William de Albany (Brian Cox) and Thomas Marshall (James Purefoy) is going to be the secret weapon of the rebels.