Shadows of past glories suffocate present endeavors in T2 Trainspotting, the long-awaited, much-delayed and disappointingly redundant follow-up to Danny Boyle's 1996 "Cool Britannia" sensation Trainspotting. Reuniting Boyle with writer John Hodge, producer Andrew Macdonald and most of the original cast — top-billed Ewan McGregor reprises his breakthrough role of the charismatically rebellious Scottish drug addict Renton — this darkly larkish, crime-flavored character-comedy will doubtless score very big on its skillfully-hyped U.K.-and-Ireland Jan. 27 bow, but looks of niche interest farther afield.

Director Danny Boyle's only film to crack $50 million in North America remains the Oscar juggernaut Slumdog Millionaire — his last two outings, Trance (2013) and Steve Jobs (2015), both underperformed — and T2 will do well to match the original's haul of $16 million ($33 million at today's prices). Opening in limited release on March 17 and wide stateside on April 7, the TriStar release will pose little threat to Disney's live-action Beauty and the Beast, featuring the dependably versatile McGregor as the talking candelabra Lumiere.

In the cumbersomely titled T2 Trainspotting — as in the first go-round — the "beast" is feral psychopath Begbie (Robert Carlyle), a snarling, battling-bantam incarnation of id with a Magnum moustache. The plot now largely revolves around Begbie's desire to gain violent revenge on his former pal Renton, who at the climax of Trainspotting made off with drug-score proceeds that were meant to be split four ways.

Serving a lengthy spell at Her Majesty's Pleasure, the resourceful Begbie liberates himself from captivity and heads back to his former stomping grounds in Leith, Edinburgh's rough-edged but rapidly gentrifying port. Here he meets up his erstwhile partners-in-crime Simon, a.k.a. Sick Boy (Jonny Lee Miller), and Danny, a.k.a. Spud (Ewen Bremner) — an ambitious, coke-snorting publican and a sniveling, smack-addled dreamer, respectively.

Begbie's escape oh-so-handily coincides with the return of Renton after a long, respectable and relatively lucrative exile in chilled-out Amsterdam, though the pair's emotionally charged and — as it turns out — decidedly violent reunion is delayed until the final reel by various plot convolutions of variable ingenuity. Very little of these have anything to do with Irvine Welsh's very fine novel Porno, upon which the film is nominally part-based — and which appeared in print 13 years ago, just a decade after Welsh's generation-defining bestseller Trainspotting came out.

The fact that there's double that chronological gap between the two films propels the characters more squarely into middle-age, though the ravages of time have been conspicuously kind to the formerly strung-out junkie Renton and the not-so-sick Simon alike. The picture is at its strongest when dealing with the volatile, unpredictable relationship between the two — which hovers between rancorous friction and knockabout affection — with McGregor and Miller clearly relishing the opportunity to relive past glories.

The bromantic bond between the pair is noticed and commented upon wryly by the only new prominent character, Simon's Bulgarian business-and-maybe-romantic partner Veronika (Anjela Nedyalkova), an ebony-haired "beauty" whose late-in-the-day confrontation with beastly Begbie sees the film briefly and belatedly generate genuine tension.

But this scene simply dribbles away to nothing, typical of a screenplay which is much too stop-start to generate proper momentum, oscillating between near-slapstick comedy and interludes of blokey sentimentality. There's an awful lot of father-and-son stuff being somewhat sentimentally worked over here, with even lion-in-winter Begbie — an irredeemably demonic force-of-nature in the first film, and in Porno, too — finally succumbing to the schmaltz.

Women are very much on the sidelines, even more so than in Trainspotting: The terrific Shirley Henderson has insultingly little to do as Spud's long-suffering girlfriend Gail, while Boardwalk Empire's Kelly Macdonald — whose sparklingly auspicious acting debut back in 1996 was as Renton's wise-beyond-her-years schoolgirl girlfriend Diane — pops up for a one-scene, two-minute cameo (which nevertheless somehow nabs her fifth billing).

Little of this will matter to the many devoted acolytes of Trainspotting, of course, which was a genuine phenomenon in its day. Oscar-nominated for best adapted screenplay, it was even ranked in a 1999 BFI survey among the 10 best British films ever made — beating out The Bridge on the River Kwai, If... and The Ladykillers. Devotees will doubtless be happy just to spend more time with these vividly remembered characters for the first time in so very long, two hours of wallowing happily and shamelessly — but counterproductively — in nostalgia.

Boyle, working with editor Jon Harris, interpolates myriad fleeting clips from the original alongside incidents, images and soundtrack choices which hark back explicitly to the first installment. But such constant memory-jogging only draws into cumulatively sharper relief the fundamental gulf in quality between the two films, and means that T2 never threatens to find its own distinctive voice.

Trainspotting, while no all-time classic, remains a bracingly and briskly opportunistic zeitgeist-surf through a time when the United Kingdom and Scotland were — after years of Conservative government — on the cusp of emerging into a new political and social era personified by PM-in-waiting Tony Blair. Twenty one years later, T2 Trainspotting has zero to say about how all that turned out, and only cursorily engages with what's going on now — a showy, self-consciously verbose "Choose Life" midpoint monologue from Renton (complete with post-synched audio) notwithstanding.

In the wake of last summer's epochal Brexit vote, and with Scottish independence prospects causing much national soul-searching, Boyle's picture — whose third act pivots on a European Union funding application — already feels instantly and strangely dated. A missed opportunity on multiple levels, T2 is stylistically an overwrought rehash which relies heavily on over-caffeinated camerawork and flashy effects (cinematographer Anthony Dod Mantle's trademark gritty flair is overwhelmed by a flurry of Dutch angles and freeze-frames) to distract us from its essential paucity of raison d'etre. Welsh's literary creations move in a scatological realm of ickily spilt bodily fluids; in such terms the film can perhaps be compared to an eager-to-please dog who knows only old tricks, contentedly licking up his own vomit.

Distributor: Sony
Production companies: Cloud Eight Films, DNA Films, Decibel Films, TriStar Pictures
Cast: Ewan McGregor, Robert Carlyle, Jonny Lee Miller, Ewen Bremner, Anjela Nedyalkova
Director: Danny Boyle
Screenwriter: John Hodge (based on the novels
Trainspotting and Porno by Irvine Welsh)
Producers: Bernard Bellew, Danny Boyle, Christian Colson, Andrew Macdonald
Executive producers: Allon Reich, Irvine Welsh
Cinematographer: Anthony Dod Mantle
Production designer: Mark Tildesley
Costume designers: Rachael Fleming, Steven Noble
Composer: Rick Smith
Editor: Jon Harris
Casting director: Gail Stevens
Sales: Sony, London

In English and Scottish English

Not rated, 117 minutes