"The Last Mimzy" is not so much based on, more inspired by, a classic SF short story, "Mimsy Were the Borogoves" by Lewis Padgett (a pseudonym used by authors and spouses Henry Kuttner and C. L. Moore), which was itself inspired by Lewis Carroll's "Through the Looking-Glass." That children are different from adults isn't news to parents, but no author(s) ever took that notion and ran further with it than Kuttner and Moore. They must have found their kids deeply weird, or vice versa.
The original short story begins millions of years in the future. The human race has found some kind of higher plane of existence, which they prefer to our own. People begin life in our ordinary sphere, but in early childhood learn the technique of crossing over "from Earth." They are taught to do this by educational "toys." An ingenious but eccentric scientist of that distant future invents a Box, a kind of time machine. Having turned on the power, he realizes that the Box is empty. The device needs a control, a 3-dimensional solid that will react to the conditions of another age so that on its return he can tell where and when it has been. By chance, near at hand are some of his son's old "toys." He stuffs some into the Box just before it vanishes into the past. It does not return. Eventually he builds another Box, filling it with the rest of his son's "toys." He sets it to travel to late-19th-century Earth. It does not return either, after which the scientist abandons the project. (The authors do not explain why his son brought his "toys" along "from Earth" if he didn't need them any more. Also, although they brilliantly imagined the "toys" as futuristic devices, they somehow could not envision a time machine equipped with miniature devices for recording picture, sound, and environmental conditions at the target site. But then they wouldn't have had a story, would they?) The second Box actually winds up in Oxford about 1862, where it is found by none other than Alice Liddell. Charles Dodgson (Carroll) records fragments of what Alice has learned from the "toys" and works them into the Alice books, especially the poem "Jabberwocky." The first verse of the poem is Alice's interpretation of the crucial datum that makes possible the technique of crossing over. But Alice Liddell is already too old, and never fully masters the technique. The first Box appears on the outskirts of an American university town in the spring of 1942, where it is found by 7-year-old Scott Paradine, the son of a college professor. He and his toddler sister Emma also learn from their "toys." Eventually, their strange behavior concerns their father, who is naturally baffled by the "toys" when he tries to investigate their properties. After conferring with a psychologist who spouts very trendy Forties psychobabble, the parents become alarmed, and take away the "toys." But it's too late: Scott and Emma have learned enough from the "toys" and proceed on their own, especially after Scott discovers the "Jabberwocky" poem in a copy of "Through the Looking-Glass." In the final scene, on an otherwise perfectly ordinary Sunday, while their father watches in shock and disbelief, the children, without fear, hesitation or regret, simply fade away, "crossing over" to that other dimension. "They went in fragments, like thick smoke in a wind, or like movement in a distorting mirror. Hand in hand they went, in a direction Paradine could not understand, and as he blinked there on the threshold, they were gone."
"Mimsy Were the Borogoves" is a brilliant story, but it is now very dated, both in style and in substance. Any modern film adaptation would of necessity be pretty much a complete rewrite, and "The Last Mimzy" is just that. It's also explicitly a "family film," and as such, the creepy, nightmare-in-bright-daylight quality of the original story is completely gone. "The Last Mimzy" is rather tame, sweet, optimistic and light, not to mention pretty clichéd: It's an eco-fable crossed with that old, rather tired plot device about how the human race, in the near or far future, has been vitiated by pollution, inbreeding, eugenics gone bad, nuclear holocaust, etc., and they need somehow to capture the vitality of the old, undomesticated human race and reinfuse it into their genetic stock. There have been so many SF novels, stories, films and TV shows with this theme that I'm having trouble coming up with titles, but the two I can think of right away are "The 4400" and a film from about 20 years ago called "Millennium," which was based on a book of the same title that I actually read before the movie was made.
The only element preserved from "Mimsy Were the Borogoves" is that a boy in the present comes upon some "toys" sent from the future, and, with his younger sister, discovers their unusual properties. Everything else is different. It's a rather sweet story in its own way, and the child actors, especially little Rhiannon Leigh Wryn as Emma, are very engaging. Probably the part of the film that works least well is the subplot that gets Homeland Security into the act, in a rather contrived effort to introduce some suspense into the story. Instead of having the children cross into another dimension, a computerized rabbit doll, Mimzy, goes back into the future bearing with "her" Emma's tears with their trace of genetic material, which of course became the basis for the regeneration of the entire human race. If you can overlook this silliness and just let the movie roll over you, you'll enjoy this mostly pleasant but inconsequential entertainment.
