Lost in my (huge) Kindle collection; can't recall title!

Fairly recent Fiction: Young graduate student works in university research library; professor who does research there is a vampire. Grad student is kidnapped by other vampires, and is saved from remote island fortress by professor/vampire and his friends. (Also vampires)

Much discussion about medieval historical figures, many of whom professor/vampire seems to have known.

I might be mistaken, but I believe this is the first book of a trilogy. All three volumes are together in one Kindle package. I switched to Audible to read a different book for a while, and when I tried to open up this readable book again, it was no longer waiting for me. Next time, I will write down the title!!

READ THIS: https://www.librarything.com/topic/329521

This sounds like it might be A Discovery of Witches by Deborah Harkness, the first in the All Souls Trilogy, at least per the first sentence of the description (I haven't read it and so can't say for sure about the second sentence).

Yes, Infoquest. It was ringing a bell but couldn’t place it. I bet it is A Discovery Of Witches