SOLVED. Childrens/YA? a young child has to find out the deaths of other children at a mansion with help from a kid he calls Einstein [s]

[Kikki]

I read it a while ago, in middle school maybe? There's a boy and a little sister and a father, the father was hired to work at a mansion and the kids come with. There's a super strict person who runs the place and doesn't want the father's kids to run around. But the boy touches an object or something and sees a different child in the past die and something something he has to find the places where all the kids died to figure something out. Near the end of the book he dives into a lake to uncover some kind of secret. There's a kid he calls Einstein who helps him a little, I think he might have had autism or something? But Einstein wasn't his real name.

I wish I could remember more, but I don't even remember how many other deaths the boy had to seek out or anything. It might have been 7 or maybe 13? I've been itching to reread the book so any help would be fantastic <3

[Leslie]

The Hunt for the Seventh http://www.goodreads.com/book/show/29...

[Kikki]

Thats it! Gosh you guys are really good at this haha thank you very much ^-^