Oskar Schell is searching for the lost sixth borough of New York. I hadn’t heard of it either, but it’s there, just as sure as Brooklyn or Queens. The sixth borough is also a metaphor, but first comes the adventure.

America’s own Atlantis is just the latest of many such reconnaissance missions, devised by a father who understands his son is different. Not different in the way Harry Potter was different, but different and special in his appreciation of pride itself. Oskar is proud of his quests and his father. He is proud of his place in a world that doesn’t understand the wonder of its own invention. No one thinks of Central Park as magical, but it is. Thomas used to tell his son a bedtime story of how the park made its springtime journey from the sixth borough to its home in Midtown Manhattan. Even when Oskar didn’t believe him, it was enough that he desperately wanted to.

A message left at 9:12am changed everything. That morning, people began to wonder if they’d ever believe in anything again. Oskar was not one of them. Not when his father left for work, nor when he rang from a meeting on the 105th floor of the World Trade Centre. And even when he called for the sixth and final time, and Oskar knew he wouldn’t be coming back, he still believed in the mission left behind. A year would pass before Oskar could again venture into his father’s study. There, amongst possessions as varied as you’d expect a professional Jeweller to have accrued, Oskar would find a key. He believed that key would unlock something in New York. He believed it would unlock something in himself.

The post 9/11 drama is fraught with the propensity for morbid sentimentality. Cynicism is easy to come by when perfectly average movies boost themselves upon still deeply-felt traumas. Some, like the affecting United 93, would arrive at it honestly, and will rightly live on as a monument. Others are better forgotten. Extremely Loud & Incredibly Close belongs more to the former than the latter, but I have sympathy for its detractors. You could write about how dewy-eyed it is in the biggest, boldest letters you could find, and still you wouldn’t have sufficiently made your point. Oskar Schell is cotton wool precociousness, who speaks like a character written and not lived. He shares with his contemporaries an untrue wisdom, voiced in run-on speeches that stop for neither man nor breath. He was once tested to see if he had Aspergers; a syndrome for the very smart who can’t run straight, his dad used to say. “The tests weren’t definitive.”

Binoculars, tambourine, and an Israeli gas mask; everything a grieving boy needs to stretch his father’s last moments to an eternity. As he sets off in search of the lock, he is chaperoned by his memories. They carry him along railway tracks and bridges, into the homes of the good and the kind. In this film, there is no other. Oskar conducts a city-wide Guess Who? game, its rules engineered to play into his endless fascination and the unfiltered manner in which he expresses it. He rages against the dying of the light, building a shrine to the family answering machine, with its recordings of calls made but never answered. It is the sound of a ghost, condemned to be play forever on repeat.

Subtlety is the first casualty in embracing accessibility; good sense occasionally another. I can’t attest to what taste there is in repeatedly referencing the tower’s so-called ‘jumpers’, but it certainly feels cheap on screen. Having conceived of this lost borough as a metaphor for the tragedy, the film did not need to extend itself to specifics, which only serves to muddy already delicate waters. Oskar himself is far less dubious, even if his artificiality is as galling as his condition – be it Aspergers or wonderment – is alienating. There is no accommodating that, since your enjoyment of the movie rests entirely on his fearless shoulders. Then again, with a certain kind of attitude, you weren’t going to like E.T. either.

As a director, Stephen Daldry gamely bridges the gap between Robert Zemeckis and Spike Lee, whose powerful 25th Hour is a surprisingly close relation, particularly in its extended coda. Both films are beholden to the human desire for closure, and of finding hope within the wreckage. Lee used 9/11 as a backdrop, while here it takes centre stage. Some will find its methods twee, others simply offensive. My own experience was far more positive. Extremely Loud is an honest movie, and many times a lovely one. It has a few surprises that feel genuine. They don’t cheat the story, which is important. There is nothing subtle about its view on the human condition, nor the likelihood of its premise. No 9-year-old would ever walk the length of New York to find a lock. But then it’s also a movie: you’ll get over it.