Sheridan Smith steps into the role of Charmian, the wife of the infamous great train robber, Ronnie Biggs. Chronicling Charmian's dramatic life, from that fateful moment when her path crossed with Ronnie (Danny Mays) as a teenager, to the devastating consequences of the Great Train Robbery in 1963. An event which left Charmian and her family on the run with one of the world's most wanted men. Facing an uncertain future in foreign lands, how long will they be able to avoid capture, with their young children in tow?