The children, who attend the Mary Erskine and Stewart's Melville Junior School, were selected by West End casting director David Grindrod to play the lead roles of Mary Lennox and Colin Craven in the award-winning musical. The pair will take part in an intensive three-week rehearsal period with director Anna Linstrum in London before the show opens in Edinburgh on December 9 for a five-week run, and they will also go to Canada when the production moves to Toronto next March.