As Noël Coward might have gone on to say: don't put your novel on the stage, Mr Faulks. It's usually a popular, but pointless, exercise to gripe about how much better the book is than the film/play/TV series. But in the case of the stage adaptation  of Sebastian Faulks's Birdsong  at the Comedy Theatre in London, which well-nigh impales itself on the original, comparisons provide the key to the performance's ultimate failure.
Faulks's 1993 novel has been read by five million people. Its slow-burning, lyrical prose tells the story of a young Edwardian, Stephen Wraysford, as he falls passionately in love with Isabelle, an unhappily married Frenchwoman, in Amiens. When their affair ends, the narrative switches to the vividly imagined horror of the battlefields of the Somme.
Ben Barnes plays Stephen in the play, and Genevieve O'Reilly his deserting paramour. Barnes brings a lanky grace to his role, but there is little sign of the passion that animates and drives Stephen's erotic pursuit. While some might find the book's Sleeping Beauty mythology problematic -- inert womanhood in need of a right royal seeing-to (I've always suspected that what Isabelle really needed was to take up an enriching hobby) -- one can at least concede that all the energetic sex in the first hundred or so pages is a thematic counterpoint to its perversion in the war chapters. The life-affirming, life-creating biology of it all is important in understanding the equally intimate details of the spilling of blood and organs on the battlefield.
But, as directed by Trevor Nunn, the lovers inhabit a starchy, sex-free zone. The fragile, porcelain O'Reilly appears quite glacially disposed towards the callow hero. There is repeated mention of heat and blood, but saying it's hot doesn't make it so. Stephen's code word for Isabelle is "pulse", but frankly we're not sure if she actually has one.
The performers are not helped in this by the compression of Rachel Wagstaff's over-slavish adaptation. We are left with a show that is too long, but equally moves too fast in an effort to glue everything in. So characters divulge innermost details on first acquaintance, with the clumsiest of prefaces: "You are a stranger so I can tell you the truth!" Sometimes the sheer speed of events leads to accidental comedy. When the gendarmes rush in and out it looks like the Keystone Kops have popped in. The book dictates that Stephen and Isabelle have a scene in the rose garden, so a trellis is duly cranked in for a 30-second appearance.
We're on marginally better territory in the episodes relating to war, thanks in part to charismatic performances from Lee Ross as honest Jack Firebrace, the sapper with a jaunty music-hall alter ego, and Nicholas Farrell as the shrewd maverick Colonel Gray. As sound designer, Fergus O'Hare in particular is able to create moments of great power: Amiens is literally blasted away. The literalism dies hard, however, and the tunnels are painstakingly and painfully represented when a flicker of light in the darkness might have sufficed. Sometimes a big budget is no good thing: it's as if Nunn and his team have lost faith in theatre's power of suggestion.
Barnes is burdened with the dual task of articulating both Stephen's and the narrator's voices: Wagstaff's tactic is simply to elide the two. Our man is liable to interpret events for us, or launch into an outraged description of slaughter, say, at inopportune moments. Stephen's broken detachment is replaced with petulance. Conversely his private thoughts and imaginings are given to other characters to spell out; scenes end up tumid with exposition, and characters warped beyond recognition. At times one could sense that the cast was going through the mill emotionally, but this emotion failed to make a break for the auditorium and into the no-man's-land of confused audience responses.
Perhaps the real love affair in Birdsong is between Wagstaff and her beloved book; to quote arguably the greatest adapter of existing stories (and Wagstaff's distant namesake), it's as if she loved not wisely, but too well. It seems fitting for a show that is so reverential towards text that its most moving moment derived not from the acting or the action, but from the entr'acte projected roll-call of the dead.