Fiona Bruce and Philip Mould investigate a charming little landscape of a French village with a river running through it, purported to be by one of the founding members of the 19th century Impressionist movement, the British artist Alfred Sisley.Its owners, Americans Kim and Chuck Van Fossan bought the work at auction near Chicago and believe it to be genuine. However, the painting was turned down nearly ten years ago by the authentication committee, so the team will have to find new evidence to help persuade them to change their mind. A lot is at stake: if the work is genuine, it could be worth over £250,000.