When the original, small-screen Singing Detective (1986) first aired in America, the quality critics were cock-a-hoop: The New York Times’ review asked, ‘Is this year’s best film on TV?’. Dennis Potter, never a man short of business acumen, wasted no time in setting up a Hollywood film remake, and by 1990 he’d written the script himself. Dustin Hoffman was pencilled in to star. But the studios got jittery, as is their way, and Potter died in 1994. Without the writer driving it, the project seemed sunk, but it’s finally materialized having been nurtured to the screen by Mel Gibson’s production company.

Should we welcome it with cheers and open arms? Well, yes and no. Certainly, getting The Singing Detective into today’s multiplexes means Potter’s work will reach audiences who wouldn’t touch a twenty year-old TV serial with a barge-pole. But inevitably it invites comparison with the original, of which it’s merely a pale shadow. Arguably, the lion’s share of the blame can be laid at the door of Potter himself. His script is basically intact (although, as he acknowledged himself, editing is the ultimate rewrite), but it’s a botched, insensitive adaptation. His onscreen alter ego, Philip Marlow, is here renamed Dan Dark, allegedly due to rights issues, but in the process losing the element of credible irony. The setting’s changed, too: Dark’s childhood flashbacks now take place in 1950s Chicago rather than Potter’s own spawning ground, the Forest of Dean during wartime. It’s understandable, but very destructive: the childhood memories feel far less soulful and personal, and much more like a detached fiction when shorn of Potter’s own personal connection. Even odder, Downey Jr himself wasn’t born until 1965, which stretches the credibility of the timeframe.

The greatest loss is simply of scope. The TV serial ran for six hours – crucially, broadcast over six weeks – allowing for digressions and organic developments as Marlow’s past, present and fiction-worlds interwove, and his mystery was gradually unveiled. Over ninety-two minutes, Dark’s road to recovery becomes a brisk sprint. No-one’s crediting the audience with enough intelligence to keep up, so every development and revelation is signalled way in advance. Within twenty minutes, Dark’s solution has been spelt out to us (and him, in some toe-curling dialogue). Another twenty minutes, and that nasty skin condition’s started to clear up. The rich diversions of the original – the Forest of Dean recollections, the hospital ward inmates – have all been sacrificed due to lack of time. The journey here is so telescoped that all the depth is lost. The whole enterprise appears inherently ill-conceived. On the small screen, the sudden fantasy song sequences felt supremely startling, but on a big screen they simply seem at home. Nor does there seem much difference between Dark’s fictional gumshoes and his Chicago upbringing; it’s simply flipping between one iconic cinematic setting and an other.

Director Gordon, once the writer of the beguiling Static (1985), has a fair stab at bringing Potter’s flawed script to the screen, but he shows to much deference to it. Undoubtedly the it’s a brave project, but it’s not especially skilful or sophisticated in execution. The performances are perfectly adequate, but the whole blend of elements resembles a very precarious pack of cards. It’s mystifying that Mel Gibson hasn’t bagged the lead role for himself, as he’d be the better choice. (Maybe he’d had enough of disfiguring facial prosthetics after The Man Without a Face (1993), but then, he’s virtually unrecognisable here anyway). Downey Jr himself may have had a troubled past, which enriches his portrayal of Dark, but he remains too young and too pretty to convince as a broken, libidinous misanthrope. Besides, was anyone clamouring to see Downey and Gibson together again after the execrable Air America (1990)?

In all honesty, although Potter was a supreme craftsman of the TV drama form – at once mastering it and pushing it somewhere new – he didn’t develop the same grasp for film writing. All that remains from the TV version is the bare bones of the plot, and it was never the storytelling that made Potter’s work so vital. It was the atmosphere and characterisation and technique, precisely the things that have been sacrificed here. The script bears many of the failings of his later work; the sense of an acclaimed writer resting on his laurels and turning in half a job with an air of ‘will this do?’. Really the greatest mystery here is why anyone should be so dogged in seeing this doomed project made at all. Almost everything that made the TV version sparkle has been excised, and what’s left doesn’t work effectively enough to stand up on its own. Consequently, you may well leave a present-day cinema screening yearning for the golden age of British TV drama.