Go back in time with No. 1 bestselling author David Walliams for a whizz-bang epic adventure of action, laughter and secret plots -- and the extraordinary friendship between a little boy and a huge gorilla that just might save the day... 1940. Britain is at war with Nazi Germany.Eleven-year-old Eric spends his days at the place that makes him most happy: London Zoo. And there?s one animal in particular he loves: Gertrude the gorilla.With bombs falling...