I'm feeling restless...

The mob who killed Hypatia were a witch-burning (or witch-skinning, as it happened) mob, not a book-burning one; they thought she had hexed the prefect of Alexandria into not attending church.

Right, none of the Christian community had anything to do with looting the library. Messy end, whatever the immediate motive.

The Serapeum was destroyed in 391; Hypatia did not die until 415.

So the witch-stoning faction had nothing to do with any prior heretical book-burning cell? Cool, they were astute revolutionaries then.