The Boy Who Harnessed the WindThe Swan Theatre, Stratford-upon-Avon★★★★☆IN our grave new world, we all need something to cheer us up. The RSC’s new feel-good “fairy tale” has the great advantage of being true.Fourteen-year-old William Kamkwambi living in a rural village in 2002 Malawi, hitherto thought of as “the breadbasket of Africa,” watched his community perish from famine caused by a combination of prolonged extreme weather conditions and political mismanagement.