Steven Knight's offbeat thriller Locke joins a spate of recent grassroots indies, including Anne Émond's shattering psychosexual drama Nuit #1 (2011) and J.C. Chandor's adventure saga All Is Lost (2013), that compensated for their low budgets with slender narratives, eschewing CGI effects that would inevitably look shoddy and tacky on shoestring budgets. This sharp approach to moviemaking outside the system essentially sets out to prove film scholar Ray Carney's old maxim that, to make a brilliant motion picture, one only needs a camera, a set of lights, and one or two actors. Like the Émond and Chandor masterpieces, Locke whittles its cast down to a slim ensemble -- one thespian -- and operates in a tight time frame. And like those other films, Locke clears the high bar that it sets for itself. The subject of the movie is Ivan Locke (Tom Hardy), a husband and father employed as a site supervisor at industrial-construction projects around England. He is the only individual who appears on camera; we take an 80-minute ride in his BMW down Britain's freeways as he ventures to a London hospital for the birth of his illegitimate child, the product of a one-time affair. As he hurtles down the expressway, he repeatedly shuffles between the calls that roll in on his hands-free. The driver performs a sweat-inducing series of high-wire acts as he tries to negotiate his way through multiple ongoing crises with increasingly exasperated callers. One involves the prenatal complications of his ex-lover Bethan (voice of Olivia Colman) -- the baby is beleaguered by an umbilical cord wrapped around its neck, and the mother literally has no one other than Ivan to show up and support her. Another involves Ivan's wife Katrina (voice of Ruth Wilson), to whom he confesses news of Bethan and the delivery for the first time. A third (to his boss) and a fourth (to an underling) concern a skyscraper job contracted by Ivan's firm for that very evening, and described as the most expensive concrete pour in the history of the U.K.; Ivan has been appointed to supervise, but has chosen to be with Bethan instead. And between conversations over the phone, Locke verbally spars with the ghost of his deceased father. Ivan's dad never materializes in the film -- either on the soundtrack or on camera -- but his presence can be felt in every frame. The father/son dynamic here brings to mind the quote that opens Robert Anderson's play I Never Sang for My Father (and the screen adaptation of the same name): "Death may end a life but it does not end a relationship, which struggles on in the survivor's mind toward some resolution which it may never find." Ivan's father is central to the film's meaning; we learn that the dad abandoned Ivan at birth and cast a long, immutable shadow over the son's life. And with a firsthand knowledge of how much it broke his own heart to enter the world and grow up as a bastard, how could Ivan even consider abandoning Bethan and his child in the maternity ward? By the end of this picture, Ivan arrives at a more intimate understanding of why his father absconded -- everything in the movie is engineered to lead up to that -- and the calls function cumulatively like some infernal test of Job, designed to drive Ivan right up to the edge of a precipice, and perhaps over. But we sense, from the beginning, that Ivan is a better, stronger man than his progenitor, and more equipped to move forward and deal with whatever life hands him. As the action unfurls, its outcome uncertain, we can only hope that our instincts are correct. That filial element is what turns Locke from a lark -- a gimmicky, clever concept picture -- into something deeper, more provocative, and resonant. The other key ingredient is Hardy's performance, which must have been maddening to pull off because all of the character's behavior and mannerisms involve such an obsessive need for control over his life -- although raw emotions slip out unchecked at the most extreme moments. Like Redford in the Chandor picture, we eventually see him break at a vexing moment, and scream out an obscenity at the top of his lungs -- the apex of his frustration. The actor Hardy most recalls here is a young Richard Harris circa the mid-'60s, and not simply due to their shared brogue: Hardy has Harris' intensity and depth of feeling as well, which, to put it mildly, are rare. He creates not simply a situational exercise, but a complex, contradictory, torn character -- one who eventually grows so multidimensional that we long to follow him into his life when the final credits roll. If any aspect of the film is a letdown, it's this. As mentioned, Locke can be viewed in concert with Nuit and Lost. The other two pictures that it recalls -- in terms of what it technically demands of Hardy -- in some ways couldn't be any more different: Anne Regitze Wivel's mesmerizing, groundbreaking short Tobacco (1996) -- which merely constitutes a three-minute pan around the head of Astrid Henning-Jensen as she smokes a cigarette in a cafe -- and Shirley Clarke's underground classic Portrait of Jason (1967), a talking-head documentary that spends nearly two hours with a camera fixed on gay African-American street hustler Jason Holliday as he riffs on his life and exploits. As in those masterpieces, the "star" has little to do other than perform with his countenance, and the film becomes a study in facial behavior, its conveyance of emotion, and its ability to slip blithely in and out of various states of pretense to accommodate the situation at hand. In its own way, this sort of thing can be ten times more demanding and difficult to pull off than a Hollywood movie with an elephantine budget, and for that reason, it's not surprising that one seldom sees it done well. The fact that Locke delivers, then, is splendid news, especially for fans of onscreen minimalism and alternative approaches to familiar stories.