In one sense, The Deep Blue Sea is the perfect film with which to close this year’s London Film Festival. It’s both timely and anticipated: not only is this the centenary year of Terence Rattigan’s birth, but this adaptation of his critically-lauded play is Terence Davies’s first narrative film in 11 years. Yet in another sense, the choice is a strange one, because at its heart, this is a theatrical rather than cinematic work. Davies’ film, set “around 1950” according to the titles, certainly doesn’t start out that way. While his script is otherwise pretty faithful to Rattigan’s, he condenses the first act into a near-wordless prologue in order to efficiently set up the love triangle that drives the plot. The camera swoops around the three leads, Hester Collyer (Rachel Weisz), her aging high court judge husband William (Simon Russell Beale) and her young, ex-RAF pilot lover Freddie (Tom Hiddleston) as they drink, fight and writhe in bed, with Barber’s Violin Concerto whirling away in the background. It feels like mid-century melodrama by way of Gaspar Noe. But once the film settles into its groove, boy, does it really settle. Every speech and pause is measured, every gesture neat, every line delivered to the back row of the stalls. Weisz and Hiddleston are experienced stage actors, and Beale works almost exclusively in the theatre, but there’s something about the sheer theatricality of their performances here that feels too stagey; even in a film as in thrall to the conventions of melodrama as this one. Even so, Weisz is terrific, and Davies’ use of low light, soft focus and faded, yellowing sets makes her look positively phosphorescent. If the critics who complained that Vivien Leigh was too attractive to play Hester in Anatole Litvak’s 1955 adaptation of the play saw her, they’d probably have a stroke. Davies takes an occasional moment to himself: both a smoky pub singalong and a wartime flashback, in which shell-shocked civilians sing Molly Malone in a London Underground station, recall his interest in songs as social glue in his 1988 film Distant Voices, Still Lives. But otherwise, this is a filmed record of a strong performance rather than a strong film in its own right. If you caught Davies’s version of The Deep Blue Sea live in the West End you’d have been delighted, but on screen it feels fusty and antique. This is unlikely to worry fans of Rattigan’s play too much, but it’s odd that a film festival’s closing gala should make you wish you spent more time at the theatre, rather than in the cinema.