Idessa hands Zanros some eulogizing notes and reminds him that accessing the library is the most important thing, and that he can callously exploit the death their friend at Mumminofrah to get that. She also gives him a dagger poked through a gilt funerary mask with some leaves stuck to it, saying, "You can give that to her. Say it's all deep and symbolic regarding the sacrifice of heroes to further the cause of Osirion against the forces of evil, or something. I made this in 20 seconds."
Idessa may or may not find Aech and head over to the library (the part they're allowed into) and have a look around, noting the precise garb of the librarians, the securities, etc., especially considering Zanros's account of his failed break in.