I am trying to buy a vehicle but the title is lost?

I am trying to buy a car from a farmer I know, but they lost the title. They bought it at a auction a few years ago and never transfered the title into their name. It has now sat in their shop for two years and they want to get rid of it, but can’t find the title. What is the easiest way to go about getting a clear title for this vehicle so that I can but it and licence it? They live in ND and I live in MN so I have to have a title to transfer the vehicle. Also they bought it at a car auction wherehouse so they don’t know who the previous owner was.