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 London Zoo. And there’s one animal in particular he Gertrude the gorilla.With bombs falling all over London, Eric must rescue Gertrude.Together with his Uncle Sid, a keeper at the zoo, the three go on the run. But while hiding out at the seaside they uncover a top-secret Nazi plot…Join David Walliams on this action-packed, laugh-out-loud adventure for all the family!