Secret Org/Library mystery with computer hacking

[Eileen]

I read this book quite some time ago (90s maybe).

It involved a group trying to find out about a secretive person or organization (perhaps a library) . I remember one of the male characters installing a key tracking program to help them solve what was going on with this person/organization.

I believe it was set in Europe, but I am not certain.

Thanks do much. I know the details are sketchy, but I remeber enjoying the book and would like to re-read it.

[Lobstergirl, au gratin]

Would you describe it as a thriller, or something else? Author female or male? Remember the cover? Author well known or obscure?

[Eileen]

Lobstergirl wrote: "Would you describe it as a thriller, or something else? Author female or male? Remember the cover? Author well known or obscure?"

I would say a thriller/mystery. I am afraid I cannot remember details about the author or cover.

It may have started with a young woman being asked to continue a mysterious family legacy.

I am afraid I could be confusing multiple novels.

I do love books about mysterious historical societies/organizations.

[Hillary]

Mr. Penumbra's 24-Hour Bookstore - main character is a man out of work in tech, goes to work a mysterious bookstore on the night shift. People come and borrow the books, they are working on a puzzle?

[Eileen]

No I read this book long before Mr Penumbra, possibly in the late 90s or early 2000s.

I did love Mr Penumbra though.

[Lobstergirl, au gratin]

Eileen, are you still looking for this or did you find it?

[Eileen]

No I never found it.

[Kris]

Eileen, how old is the protagonist (e.g., teenager, adult in 20s)? Most likely a female? Skilled in martial arts or weapons? Any romance?