The real world, just as the world of J.K. Rowling’s phenomenally popular Harry Potter books, can be divided into Muggles and witches (or wizards). Muggles are non-magical humans who live oblivious to the fact that their society is infiltrated by a population of those who practice incantations and potion-making. Real-life muggles are the non-believers, the ones not indoctrinated into the ineffable charm of Rowling’s realm, while witches and wizards are the ones who love literally everything associated with the magically gifted, tousle-haired, bespectacled pre-teen with a lightning bolt scar on his forehead.

When the first installment, The Sorcerer’s Stone was translated to film, it was decidedly not aimed at magic folk. Director Chris Columbus was charged with the onerous responsibility of introducing Rowling’s magical world and weaving in a plot involving the return of the evil Lord Volemort. In cramming in both necessary elements, the film felt like an animated stick figure, a conglomeration of bare bones allusions to the novel’s major dramatic moments that did not satisfactorily flesh out details. The production design, while otherwise superb, nearly crumbled under the weight of tacky, poorly realized special effects. All this made the movie feel like a project rushed through production to cash in on the Potter craze. The movie succeeded largely on the momentum of Rowling’s staggering imagination and brilliant performances.

There has been a wholesale reprisal of responsibilities from Sorcerer to The Chamber of Secrets, from director Chris Columbus, through the cast and all the way down to production design and costuming. With this second time around, the ensemble has grown and learned along with the kids—now taller, bulkier and with noticeably deeper voices—and rectified many of the problems with the first year’s installment, with seamless special effects, superlative performances and staggeringly sumptuous visuals. Columbus glosses over exposition in Chamber—making the first film necessary viewing—and so is able to put more meat into each frame now that he’s afforded the luxury of focusing solely on plot. Virtually every major event makes it from page to screen, but the effort never feels like a cursory treatment. Quite to the contrary—it is a more fully realized, weighty and compelling tale.

If The Sorcerer’s Stone wasn’t satisfactory as an introduction to the Potter world, then the second installment, The Chamber of Secrets is much more accessible and certainly less hurried (after all, it does clock in at a child-resistant two hours and forty minutes). It is also steadily plotted, driven by brilliant action sequences—including a breathtakingly visceral Quidditch match—and many moments of real tenderness. The story finds Harry nearing the end of his summer holidays following his first year at Hogwarts School of Witchcraft and Wizardry and living with his Muggle relatives, the detestable Dursleys. Despite a visit by a Dobby the servant house elf, who warns him of the imminent danger of returning to Hogwarts for the upcoming semester and his second year of education, Harry returns to school with the aid of his best friend Ronald Weasley (Rupert Grint) and a flying Ford Anglia. At Hogwarts, Harry encounters a fresh set of intrigue, both expected and unexpected. Harry’s other best friend, Hermione Granger (Emma Watson) is still top of the class, but the Defense Against the Dark Arts teacher has been replaced, his nemesis, Draco Malfoy (Tom Felton) is now seeker for the Slytherin Quidditch team (a wildly popular magical sport played on flying broomsticks). Most terrifying of all, the Chamber of Secrets has been opened once again. The chamber in question was built by Hogwarts co-founder Salazar Slytherin and housed a monster that fifty years ago terrorized the school and killed a muggle-born student. Now, the monster is literally petrifying pupils and threatens to permanently shut down the school as Harry, Ron and Hermione attempt to uncover the mysteries surrounding the Chamber.

With its sinister plot and dark magic undertones, Chamber is frequently a much darker concoction than the frothy, lighter-than-air stuff that was its predecessor. Murderous voices emanate from walls, legions of spiders scuttle through broken window panes and epithets scrawled in blood appear on hallway walls, foretelling imminent doom to students. This evil takes a more palpable form in the guise of Lucius Malfoy (Jason Isaacs), Draco’s father, a pale, embodiment of evil who drips with malevolence. He is but one example of the pitch-perfect casting and superbly restrained performances delivered by the supporting cast, which is a cavalcade of British acting luminaries. Dame Maggie Smith returns as the cantankerous yet kindly Professor McGonagall, while Robbie Coltrane provides a comic foil as the lovably gruff gamekeeper Hagrid. Simultaneously though, moments of hair-raising creepiness are offset by the considerable humor throughout, provided largely by Kenneth Branagh’s portrayal of new Defense Against the Dark Arts professor, Gilderoy Lockhart. Branagh positively revels in Lockhart’s self-obsessed dandy dress and mannerisms, a perfectly effected over-the-top caricature oblivious to the sinister events transpiring around him. Ultimately though, despite the movie’s ineffable fun, it is difficult to view Chamber without a certain sense of regret and loss over the death of Richard Harris, who played Hogwarts headmaster Albus Dumbledore and earlier this month succumbed to Hodgkin’s disease. His Dumbledore was invested with a gritty warmth and whispery intensity, a benign, profoundly humane headmaster who displayed real pathos. His work on the Potter films was among his last, and it is hard to imagine the next installment without his contribution. Indeed, it is intriguing to consider what will become of the Potter franchise, now that Columbus is assuming a producer’s role while Alfonso Cuaron (of Y Tu Mama Tambien fame) takes over the helm for the third film, The Prisoner of Azkaban. The series is critic-proof, but it hardly matters—you’d have to be the worst sort of Muggle imaginable not to delight in the Potter fantasy.