Dudbridge starts right in the middle of Chinese history, with the Song emperor Tai Zong's attempt, from his accession in 976, to build up what we might now call "a national library". This involved an appeal to find missing books, using a much earlier catalogue as a reference. The history of book destructions, going back to the famous Qin burning in 213 BC, suggests that transmission was more important than destruction, since with paper scrolls in wooden libraries the latter was almost inevitable. Song compilations such as the Imperial Reader and Extensive Records were among the earliest printed works and, with their qualitatively different survival modes, preserve the fossilised traces of earlier hand-copied works, some directly sampled and some taken from previous encyclopedias. They are "gateways to lost medieval literature".
The second and third lectures look at examples of works which saw "neither full transmission nor full loss" — which can be partially reconstructed. Qiu Yu, a private historian writing early in the 8th century, produced Summary Documents of Three Kingdoms, an account of historical events in the mid-6th century. We can recover about a tenth of this, using excerpts in the Imperial Reader and a later chronology. It presents "a distinctive early Tang vision of the last fifty years of disunion" and its transmission failure is likely the result of this being incompatible with Song ideas of imperial legitimacy.
Four Gentlemen of Liang, also written in the 8th century but set in the mid 6th, is a series of stories about four scholars who appear at the court of Emperor Wu of Liang and show off their skills and knowledge in various contests and trials. Its use of irony and its mix of skepticism and matter-of-fact presentation of the fantastic made and make it hard to classify: could it be "a kind of medieval science fiction" or perhaps a concealed satire? Although we can reconstruct a large part of its text, Dudbridge suggests that this work is "truly lost" because we can't reconstruct a context for it, or an association with "any known or acknowledged genre of medieval literature".
These two partially reconstructed minor works have their own interest as history and literature. Their significance in Lost Books of Medieval China, however, is as a guide to "the potentials and the limitations of Chinese textual tradition in recovering loss over the past thousand years". A topic which Dudbridge manages to make both fascinating and accessible to non-Sinologists.