It's an anti-war biopic of the English poet Siegfried Sassoon that covers Sassoon's life from 1914 to the 1960s.
Siegfried Sassoon (Jack Lowden/Peter Capaldi) was a Second Lieutenant during World War I. His younger brother, Hamo (Thom Ashley), is killed during the war. Siegfried is further horrified by the tremendous human toll in death and lifelong disability caused by military leadership in which he no longer believes. Already a well-known poet, he refuses further participation in the war and is sent to the Craiglockhart War Hospital near Edinburgh technically for shell shock. There Siegfried meets and befriends Wilfred Owen (Matthew Tennyson), a much younger man. Siegfried also explicitly recognizes his own homosexuality.
The film then follows his anti-war sensibilities through snippets of his poetry and his chaotic love life, mainly focused on Ivor Novello (Jeremy Irvine) and Stephen Tennant (Calam Lynch/Anton Lesser). At a certain point, he tries to escape the chaos by marrying Hester Gatty (Kate Phillips/Gemma Jones). Together they have a son. George (Richard Goulding), but clearly, the marriage does not heal Sassoon's memories.
The film uses footage from the trenches in World War I and occasionally flips in time between the young Sassoon and the elderly Sassoon. Some of the editing decisions made little sense to me, particularly the early scene forecasting his conversion to Catholicism. Some edits made the film more complex than necessary. Nevertheless, the movie successfully portrays Sassoon as disabled because of World War I, from which he never psychologically recovered. This is clear from the multiple references to Wilfred Owens' poem, "Disabled."
