In the 1940s Guthrie began to direct operas, to critical acclaim, including a realistic "Carmen" at Sadler's Wells and the Metropolitan Opera in New York. He also returned to Scotland where, with James Bridie in 1948, he staged the first modern adaptation, by Robert Kemp, of Sir David Lyndsay's grand-scale medieval comedy "Ane Satyre of the Thrie Estaitis" for the Second Edinburgh International Festival; a landmark event in the modern revival of Scottish theatre. Staged in the city's General Assembly Hall of the Church of Scotland on the Mound, specially adapted for the occasion, it was here that Guthrie's hallmark thrust stage first proved its full worth.