The opera, set in an unspecified time, revolves around a periodic tribunal at which Clio, the classical Muse of History, reappraises the reputations of historical figures. Aethelred, who has slept contented in his mediocrity for a thousand years, is jolted awake by his ambitious consort, Emma, and ordered to do whatever he can to improve his standing in the eyes of posterity. Apart from his own reluctance to undertake the task, Aethelred has to deal with Clio's shockingly poor memory- she forgets names. Even William of Malmesbury, who plays a major role in the opera, is too busy ratting off the exploits of his favorite Saxon kings to pay Aethelred much attention. In the end, after a Publicist and Hypnotist fail to galvanize the king by transforming him into an orator with a series of charmed words, Aethelred finds contentment in playing a wistful solo on Clio's trumpet, which the muse has absent-mindedly left behind.