The John le Carré thriller that came in from the cold

Before John le Carré's death in December last year, his youngest son Nick Cornwell promised he would complete any work the spy writer left unfinished. Two months later, the sci-fi author was locked down at the family home in Cornwall when he dug out the thriller his father had written and set aside seven years earlier. Writing exclusively for the Daily Express as Silverview is finally published to rave reviews, he reveals the poignant story behind le Carré's missing book.