Ripley Under Ground is the second novel in the Ripliad by Patricia Highsmith.
Eight years after the events of the first book, Tom Ripley is now in his early 30s, living a comfortable life in France with a rich wife, Heloise. His lifestyle is supported by an art scam whereby new paintings by a dead artist, Derwatt, are being produced and sold through a gallery in London. Ripley is the sleeping partner in the business, but when an American collector appears questioning the authenticity of the new works, he is forced to act (violently). The scam is complicated by the intervention of the man forging the paintings, who wants to confess to appease a guilty conscience. Ripley, who is of course unfamiliar with guilt, will resort to anything — even murder — to dissuade him.