Ridley Scott’s film about the machinations behind the months-long, desperate efforts to free the grandson of J. P. Getty, then the richest man in the world, after the boy’s kidnapping in 1973, may be remembered mostly for its uniquely convoluted production. As most viewers will be aware, “All the Money in the World” had been completed with Kevin Spacey playing Getty, but after the actor was accused of sexual misconduct and shunned as a result, Scott elected to jettison all his scenes and quickly reshoot them with Christopher Plummer, while adhering to the original release date. He succeeded.

That’s a remarkable achievement, certainly more so than the actual movie Scott has ultimately crafted—a visually elegant parable of misguided wealth, but one considerably less exciting than one might hope, and not always in accord with the historical record. One admires Scott’s ability to reedit the film in response to circumstances more than the actual result of his having done so, which amounts to a rather thrill-free thriller, shot in gray, somber tones by Dariusz Wolski but slackly edited by Claire Simpson.

The picture, scripted by David Scarpa from a book by John Pearson, begins with the abduction of sixteen-year old John Paul Getty III (Charlie Plummer), then living a bohemian life alone in Italy, from a seedy street in Rome. Trundled off in a van, he’s transported to a mountain cell in rural Calabria, where he’s chained to the wall while his captors, the most prominent of whom is a fellow called Cinquanta (Romain Duris), inform his mother Gail Harris (Michelle Williams, for some reason adopting an accent that makes her sound vaguely like Katharine Hepburn) that he’s being held for $17,000,000 ransom.

Cue a flashback that provides the familial history. Young Paul is the grandson of billionaire J. P. Getty Sr. (Christopher Plummer, no relation to the younger Plummer), who—we’re shown—made his fortune in the Saudi oil fields and wants to part with none of it, except to purchase the fabulous artworks that will eventually find their way to the museum that now bears his name. The old man had been estranged from John Paul Jr. (Andrew Buchan), an alcoholic failure with whom Gail had three children (Paul being the oldest), until Getty Sr. for some reason offered him a job at the family firm.

The elder Getty welcomed the family to Rome, where he took a particular liking to seven-year old Paul (Charlie Shotwell), who took an eager interest in helping the old man draft dismissive responses to pleading letters from folks begging for money. In one of the picture’s eeriest, more effective scenes, he even took the boy to visit the ruins of Tivoli, the Roman Emperor Hadrian’s villa; there he explains to the lad that he actually was Hadrian in an earlier incarnation.

Unfortunately J.P. Jr. proved unequal to his job’s demands, being more interested in drugs and drink than work. So Gail divorced him, taking full custody of their children in lieu of any payment from the Gettys except for child support. So now, back in 1973, Harris found herself confronted with a huge ransom demand for her son, but no money to pay it. Naturally she approached her former father-in-law for the cash, but he refused to provide anything, acting not only as a result of his penny-pinching ways but because—as he explained publicly—paying would only invite the kidnapping of his other grandchildren.

He does, however, appoint his fixer Fletcher Chase (Mark Wahlberg), an ex-CIA man, to look into the matter. Chase uses his contacts to secure a meeting with some Red Brigade leaders—thought to have been the perpetrators. But they inform him that young Paul used to talk about staging his own abduction to extract money from his grandfather. When told that, the elder Getty is even more resolved not to fork anything over.

That causes consternation among the kidnappers, some of whom are actually killed in a police raid, but not before selling young Paul to a more brutal gang leader, who famously sent the boy’s severed ear to an Italian paper as a ghoulish proof of life. That finally induced J.P. Sr. to come up with some cash—though much less than the criminals demanded, and with strings attached. The boy was eventually released some five months after he was originally taken.

As cobbled together by Scarpa and Scott, much of “Money” consists of long sequences of Gail and Chase trying to work together to find out what’s happened to Paul and secure his release, juxtaposed with scenes of the captive Paul and Cinquanta, who grows increasingly protective of the boy. Williams is good at playing the cultivated, concerned mother, and young Plummer and Duris handle their side of the equation well, with the ear-severing scene registering the horror of the bloody deed. But most of these portions of the movie are curiously flat. Even those that seem dramatic addenda to the actual course of events—like young Paul’s escape attempt, and particularly the big chase sequence at the close that’s apparently invented out of whole cloth—don’t register as strongly as they should. (An episode in which Gail tries to raise the cash she needs by selling a supposedly valuable statuette the elder Getty had once given Paul does, however, achieve a darkly humorous tone.)

Wahlberg, moreover, seems completely miscast as Chase, weighing down every scene he’s in. His discomfort is evident in his frequent pairings with Williams, but becomes even clearer in the few he shares with Christopher Plummer who, however short the preparation time he had for the film, delivers a magisterially creepy performance as J.P. Sr. It’s a capstone to a career that in his twilight years has really become golden, a series of outstanding turns in pictures that are rarely worthy of them. He’s the primary reason to see “All the Money in the World,” though one can’t but dream of the possibility of someday comparing his treatment of the part with that of the discredited Spacey.

Scarpa and Scott engage in another bit of dramatic license when, in addition to fashioning that prolonged chase to make Paul’s release more cinematic, they suggest that J.P. Sr.’s death virtually coincided with it: actually he lived until 1976. They also decline to report the tragic life that Paul lived after his experience.

In sum, this “Money” isn’t all it could be; it’s a disappointment in view of the talent involved, despite stellar work from the elder Plummer and, to a lesser extent, Williams. Perhaps the upcoming television mini-series “Trust,” starring Donald Sutherland as J.P. Sr. and Hilary Swank as Gail, and directed by Danny Boyle, will prove more satisfying in the long run.