Siegfried Sassoon – war hero, conscientious objector, pacifist, homosexual and, latterly, Catholic – has long been a rich seam to filmmakers, biographers and novelists alike. But the problem must surely be this: which seam in such a rich garment of a life does the creative mind hem to best effect? In Terence Davies’s latest biopic of the poet, Benediction, it is hard to tell which thread wins out. In a mélange of tableaux consisting of acted scenes edited by Alex Mackie, archival footage of the trenches showcased in symmetrical, widescreen images and superimposed poetic sequences set to the music of Stravinsky, Gershwin and music-hall staples by Ivor Novello, the young Sassoon emerges ebullient and questing from the barbed wire and mud of Picardy.