Eric Gillain
Eric Gillain is considered to be one of the best bibliodetectives in Nafrece. He earns his living by searching rare books and, in fact, can find any of them. He himself states to Margaret that he just has a gift for searching.
When a teenager, he committed a murder in order to defend his sister and was sent to prison. However, he lost his memory due to the shock he experienced and later was able to live “in a normal way”. Eric was said to be able to regain his memory only in case he could experience the same shock again. Finally, he regained it after the hints he got.