Benediction: Terence Davies’ Siegfried Sassoon portrait is a film of waning power

► Benediction is in UK cinemas and on Amazon Prime from 20 May.

Following A Quiet Passion (2016), his intensely interior film about Emily Dickinson, Benediction is Terence Davies’ second consecutive portrait of a poet: in this case, Siegfried Sassoon, who was born in 1886 – coincidentally, the year of Dickinson’s death. Like its predecessor, the new film juxtaposes the earlier and later life experiences of its subject, with Jack Lowden and Peter Capaldi sharing the role of Sassoon. But where A Quiet Passion offered a richly imagined evocation of Dickinson, Benediction does not illuminate Sassoon’s circumstances with comparable insight.

The film’s highlights are all in its first half. Opening in 1914, with a confident pan down the front of a theatre, Benediction begins at the London premiere of The Rite of Spring, as Lowden’s voiceover quotes Concert-Interpretation, Sassoon’s poetic response to Stravinsky’s piece. The date is dubious (The Rite premiered in London in 1913; Sassoon’s poem responded to a 1921 concert performance) but the symbolic significance of beginning the film in the first year of World War I and at a crucial moment of Modernist artistic expression is apt.

This striking opening is followed, though, by a disjointed sequence that hastily attempts to sketch in Sassoon’s war service (via archive footage and voiceover), and the controversy following his 1917 Soldier’s Declaration against the war – plus a church-set lurch into the poet’s future. In contrast to Davies’ customary sensitivity to time’s passage and the associative workings of memory (and to the haunting, stylised WWI sequences in his 2015 Sunset Song), these choppy scenes lay insufficient groundwork in terms of conveying Sassoon’s war experience, and Benediction doesn’t settle into a satisfying rhythm until Lowden’s Sassoon arrives at Craiglockhart Hospital.

While this period of Sassoon’s life is familiar from earlier fictions – notably Pat Barker’s Regeneration, filmed by Gillies MacKinnon in 1997 – it emerges as freshly engaging here. The scenes between Sassoon and the psychologist W.H.R. Rivers are particularly strong, aided by Ben Daniels’ beautifully warm and wry performance as Rivers, and by some of Davies’ finest writing, including one of the most tender, understated expressions of gay solidarity ever put on film, communicated through a quiet moment of sympathetic recognition between the two men. Moments featuring Matthew Tennyson as Wilfred Owen aren’t developed enough for the dramatic use the film seeks to make of them (a tragic thwarted love story between the writers is implied). But one poignant and quintessentially Davies sequence, at a soldiers’ singalong to Waiting at the Church, expresses Sassoon’s pain about Owen’s imminent return to the front.

Benediction is weaker in the post-war scenes, where Sassoon’s turbulent relationships with Ivor Novello (Jeremy Irvine) and Stephen Tennant (Calam Lynch) are centred. An account of Sassoon’s complicated love-life could be rewarding, but the film becomes a monotonous series of arguments between lookalike lovers over-enunciating barbed quips, with little attempt to explore the relationship dynamics or Sassoon’s attraction to these partners. Every other character speaks as if they’d just popped out of a Wilde or Coward play, with dialogue that defaults to strained epigrams. The characterisation of Novello, for example – presented solely in terms of insolent caddishness – gives Irvine only one note to play.

Andy Harris’s production design is handsome but the film’s evocation of post-war queer experience, with Bright Young Things exhibitionism offset by a brief reference to “the shadow life” necessarily lived by gay men at the time, finally seems superficial, as does the treatment of Sasson’s decision to marry a woman and his later-life conversion to Catholicism. If anything, the arch tone of the second half mostly suggests a variant on The Boys in the Band – albeit one that’s ‘Typically English’, to quote the satirical Newley/Bricusse song featured in the last of the film’s performance interludes.

Lowden brings to the film the association of past roles: his Nikolai Rostov in War and Peace (2016); his German soldier in The Passing Bells (2014). But investment in Sassoon as a protagonist wanes thanks to the film’s slack rhythms. Capaldi glowers through poorly pitched father/son conflict scenes, with some temporal transitions achieved by ropy visual effects.

But perhaps the biggest disappointment is the scant attention paid to Sassoon’s creativity. A few poems are featured – somewhat randomly – throughout, but it’s not enough to give a sense of the writer as both artist and activist. Lacking the fluidity and richness of the director’s best films, Benediction makes its protagonist less as an animated individual than a symbolic victim figure. A flashback coda pins Sassoon firmly in his past, forever a casualty of an experience of war that the film never truly makes vivid.