In the conversation, Lirael explains that librarians are sometimes called into action to face threats lurking within the ancient, vast Library. This library holds many dangerous and mysterious items, including creatures, powerful or hazardous knowledge, and artifacts crafted recklessly. It emphasizes that these objects are dangerous and should only be approached with caution and preparation.

She highlights that some books and objects are so perilous that they should never be opened, underscoring the library's role as a repository of dangerous knowledge and artifacts. The library's age and depth mean it contains many secrets and dangers, which can sometimes require librarians to defend or safeguard these secrets from misuse or harm.