In the years before the war, Sylvie Charlot was a leading light in Paris fashion with many friends among musicians, artists and writers. Now she is largely forgotten. Spending time in Paris during a break in his acting career, Colin Mallory sees a striking portrait of Sylvie. Some think it is a late work by Edouard Vuillard but there is no signature or documentary evidence to support this view. The picture has some unusual qualities, not least the presence of a shadow of something that cannot be seen. Perhaps the picture was once larger. Colin feels an odd sense of connection with Sylvie, who seems to be looking at him, appealing to him, wanting to tell him something. Despite a warning not to pursue his interest in her portrait, he is determined to find out more about the painting, who painted it, and why it was hidden for many years. Colin's search takes him back to the film and theatre worlds of Paris and London in the 1930s - and to a house in present-day Sussex. As he uncovers the secrets of Sylvie's past, her portrait seems to take on a life of its own.