Fiona Bruce and Philip Mould investigate a mysterious canvas which could be by a pioneer of Abstract Expressionism, Arshile Gorky. Works by this Armenian-American artist fetch millions at auction, but there is one major hurdle in the way of owner Liza Dunluce realising its fortune - the canvas is covered in white paint.Dates on the back of the canvas suggest it was painted between 1928 and 1931, but the composition visible through gaps in the white paint looks nothing like Gorky's work from this early period of his career. Philip hopes an X-Ray will explain why the dates on the back of the canvas don't match the style of the painting. Could there be another, earlier work buried deep beneath the layers of paint?Tantalisingly, Fiona's research reveals a lost Gorky from the 1930s, known only by a photograph. Could this picture lie hidden beneath a 1940s composition?Events take a turn after the Gorky family go to see the picture and raise a startling question: should the white paint layer actually be removed at all? The artist's granddaughter, Saskia Spender, tells Fiona that Gorky sometimes used white paint to partially cover up his pictures as part of the creative process. Could Liza's canvas may be made up of not one, not two, but three pictures - the white layer on top being a further composition?This proves to be one of the most challenging investigations on the series yet. With millions at stake, will Liza's picture turn out to be neither fake nor fortune?