Dame Peggy Ashcroft, about to return to the stage of the Royal Shakespeare Theatre as the Countess of Rousillon in a new production of All's Well That Ends Well talks to Michael Billington, drama critic of The Guardian, about her changing theatrical life and times, from her first appearance in London over half-a-century ago to the 80s, with her award-winning television performance in Stephen Poliakoff 's Caught on a Train.