It's been five years since Wes Anderson gifted a live-action film unto the world, and that's far too long. Sure, Fantastic Mr. Fox, his stop-motion animation adaptation of a Roald Dahl story, was a charming little confection, but it was, y'know, for children. We've long been ready to see some grownup Wes Anderson again, which is why his latest film, Moonrise Kingdom (opening in New York and Los Angeles this Friday), is such a welcome relief. Even though, well, it's about kids.

Though Anderson has previously grafted his grainy, 8-track-era aesthetic onto the ocean wilderness and the sprawl of the Indian subcontinent, the small, rocky New England island that the people of Moonrise Kingdom call home feels, in some sense, like his most exotic locale. The year is 1965 and a 12-year-old boy named Sam (delightfully odd newcomer Jared Gilman) has just run away from his Khaki Scout (they're like the Boy Scouts, only a little more regimented) camp on the delightfully named New Penzance Island, an early-autumnal place with no paved roads and airplane-delivered mail. With New Penzance, Anderson has lovingly created a world that is both cozy and lonely, the kind of just-short-of-desolate bit of land that one can easily find in the real-life waters off of Maine or Nova Scotia. (The movie was filmed in Rhode Island, which turns in a lovely, aching performance.) Those dual, sometimes conflicting spirits — a homey sort of simpleness and an isolated ennui — lend the movie a wistful tone that isn't quite bittersweet, let's call it semisweet. Whatever comes before it, the sweetness is certainly there; after all, this is a story of  children teaching adults how to love again. These are potentially treacly woods to be navigating, but fortunately Anderson is a confident and resourceful leader.

It turns out that young Sam has set off across the island to meet up with a girl he met the year previous, when both were at a church pageant in the town on a nearby bigger island. Suzy (Kara Hayward, another great find) is a depressive, sometimes wild girl who lives a classically Andersonian life -- bookish, shabbily elegant -- in a red and white lighthouse with her parents (Frances McDormand and Bill Murray) and three young brothers. The house is filled with the sounds of Benjamin Britten's The Young Person's Guide to the Orchestra while Kara spends most of her time reading young adult fantasy and sci-fi novels, meticulously crafted props with whimsical titles and note-perfect artwork on their covers. Suzy wants out, Suzy wants an adventure, and, after exchanging letters with Sam continuously since their first encounter, is finally presented with that opportunity. And so these two kids, who speak and react with the deadpan blankness of many an Anderson creation, gambol off into the woods, where Sam can show off the survival skills he learned as a Khaki Scout and Suzy can read to Sam from her books and teach him about French kissing.

Meanwhile, Sam's scout leader Ward (Edward Norton) is on a mildly desperate hunt for the boy, and enlists the help of his adorably ragtag scout troop and the island's sadsack bachelor policeman, Captain Sharp (Bruce Willis). And that is our film's little adventure, with McDormand and Murray, who are having marital troubles, joining the chase and Tilda Swinton popping up briefly at the end as a Social Services officer intent on taking Sam, an orphan, to a juvenile reform center. The tone is almost that of an action thriller, but of course in the lo-fi-est of senses, which is one of the film's bigger, broader jokes. But it's a serious point, too. The stakes are high because these are the only stakes these people — the bored adults, the kids who are just stumbling into the light of the world — really know. They live on a small island and are mostly islands themselves, until of course Sam and Suzy eventually show them that, in some ways, loneliness and other emotional ills are self-imposed. (At one point McDormand's character tells Murray's to stop feeling sorry for himself. "Why should I?" is his mournful response.)

The movie is laced with a simple message about change and time, one that Anderson sneaks in delicately. What is ostensibly a kiddie adventure comedy has been infused with something knowing and weary — Anderson's precious objects, all his throwback knickknacks and costumes, are just as precious in Moonrise Kingdom as they are in his other movies, but here they are more clearly melancholy totems of an unretrievable past, there's a new weight to these curios that we haven't felt  before. (Hence the period setting, maybe.) Anderson, 43, is entering middle age, so perhaps this sweet-sad paean to youth was to be expected. His movies have always to some extent been about aging and the past, but here they are his chief themes, carefully handled and imbued with his trademark wit.

Aside from tackling the sobering realities of time, the movie is, as one would expect, chock full of glorious little details that hum with vibrant and quirky (in the best possible way) life. In a lovely sequence wherein we learn the contents of Suzy and Sam's letters to one another, we see Sam at his foster home with a pack of his fellow foster brothers, white T-shirted greaser teenagers, engaged in a series of background activities -- their presence gives perfect time and place context without overstating. Bob Balaban, serving both as narrator and island historian, is decked out in the comfy but rugged L.L. Bean-ish gear that is practically the uniform of coastal New England. In fact, Anderson gets so many details about this chilly/dreamy milieu so perfectly right that I had to keep reminding myself that he grew up in Texas, not on the rocky shores of Vinylhaven. To my New England-biased mind, this maritime idyll is the most winsome and emotionally realized of all of his wacky settings, one that's of course cute and bright and cluttered, but also creeps with a wintry foreboding. I want to live on New Penzance Island but suspect I'd get sad there after a month. Which is sort of Anderson's point, I think.

As is also de rigeur with Anderson movies, the film is enlivened by textured, understated performances from its ensemble. It's always such a joy to see Willis with his tough guy stuff dialed down and his smarter, more sensitive side turned up. His character becomes, in some ways, the film's grownup hero simply by being a decent guy who tries to behave decently, which Willis plays with a kind of lurching grace. Norton remains a master of soft-spoken fluster and McDormand fills her scenes with her brusque pragmatism. Really, though, the film belongs to Gilman and Hayward, who aren't exactly acting, maybe, but are so well chosen, so well directed, that they seem to grasp the bigger things — wispy, aching wishes and all that — that should only be wearily understood by us adults.

Moonrise Kingdom, for all its beauty and wisdom, is still a rather slight film. It doesn't feel as expansive as The Royal Tenenbaums or as soul-searching as The Life Aquatic. But for what it is, a little lonely island of a thing, it's a clever and curious success. I'm awfully glad to have Anderson back in the real world. Well, back in his version of it, anyway.