The years have not been kind to Agravaine—he looks much older than his forty-five years and has become a drunk. Mordred, meanwhile, looks the same as ever—a thin, wisp of a man decadently dressed. The two are in the cloisters of the Orkney palace at Camelot. They are arguing over the best way to start a rebellion against the king. Mordred's hate for Arthur knows no bounds; he wants to rebel because Arthur slept with his mother and then left Mordred to die. Agravaine argues with him, saying his personal feud with Arthur will never motivate any kind of rebellion—the reason needs to be something larger, more political, that all men can get behind.
Agravaine's advice to Mordred is intelligent—just as Merlyn spoke to Arthur about years before (although for very different reasons), to succeed in a revolt/warfare, you must have a stated reason larger than something personal so that multitudes of people can support and justify it—although the real reason may still be something personal. This is a direct illusion to the mechanisms at work in the Nazi party during WWII: the personal ravings of one man turned into a national political movement.
The conversation moves to the subject of Lancelot—whereas before, Mordred had been enraged and Agravaine indifferent, now they are reversed. Agravaine raves about Lancelot's infidelity with the Queen. Suddenly, however, Agravaine has an idea: suppose they were to raise the issue of Lancelot's infidelity under Arthur's new judicial laws; Arthur would have to do something about it then. Doing so, Arthur's power would be split and then would be their chance for revolt.
Agravaine suggests they manipulate Arthur's new judicial laws so that Guenever is tried by a jury rather than in trial by combat. It is Arthur's tragedy that his political innovations to uphold justice will be used by those working, not for justice, but solely to destroy his reign. The Orkney clan has found a way to continue to pursue their feud even within the England that has been transformed to a land of "justice".