I mentioned earlier that Niko and Tess have a butler. This is him. Adam Graves.

Graves, despite (or perhaps because of) being a hunchback, maintains a an air of dignity and quiet civility at all times, and has faithfully served the Lahner household for generations.

You see, although he is not a scientist himself, he has picked up quite an extensive knowledge of medicine, and was in fact a surgeon long ago, before he entered into the service of the Lahner family. Working for them only increased his knowledge of the living body, and how to keep it that way. Despite the fact that he could in all probability find gainful employment in practically any hospital you could name, he insists on remaining the Lahner family's butler.

His responsibilities include cooking, cleaning, and helping Tess make sure her brother eats three whole meals everyday, as well as tending to any guests they might have (although this is rare as most people are put off by Niko's disposition). Although he doesn't show it very often, he cares deeply for their well being, and is very loyal.

His relationship with his fellow employees however, is somewhat less enthusiastic. He sees looking after Francois as an unnecessary chore (there is more than enough room in the M.S.A.'s insane asylums for there to be any excuse for him to stay in the manor), and treats the Spalling brothers with disdain, saying that the day those two amount to anything will be the day he straightens his back.

His name is a reference to something. See if you can guess what.