Modigliani. Unarguably one of the greatest artists who ever lived. Modigliani's women. Those elongated, haunting figures, as eternally provocative as the Mona Lisa. Adn Modigliani's missing masterpiece. A priceless lost treasure - or a chillingly dangerous game? Up and coming artist Peter Usher has still to exhibit anywhere, still to make even the most modest mark on the London art scene. But a...