There were at least four Gabriel Knight games but one of them was a remake of the first one

The first one was about solving a voodoo ritualistic sacrifice murder case

Thefirst one is highly educational and teaches about the history of voodoo or hoodoo

I strongly recommend playing or watching a let's play video of the first one and it's remake

There can be a large amount of hours listening to people talk about voodoo whej you interview them

They make it entertaing and use good voice actors