“Is it the terrorists?” a frightened child asks, because that is the scariest thing she knows. But what makes this thing scary is that it is something no one knows. It is beyond our knowledge, even beyond our imagination. Earth is under attack and no one knows by whom or what they want.

These are not the “let’s play musical notes together” aliens of Close Encounters of the Third Kind or the Reese’s Pieces-loving, bicycle-flying botanist alien from E.T.: The Extraterrestrial. There’s no “Take me to your leader,” or Klaatu Barada Niktu. These aliens don’t even want to keep humans on as slave labor as in Battlefield Earth. They don’t want us to understand or negotiate with them. It does not seem to be about power or plunder. They just want to destroy us. As one character says, “This is not a war any more than there’s a war between men and maggots. It’s an extermination.”

Steven Spielberg knows two things better than anyone else who ever made a movie, and both are in top form here. First is his extraordinarily evocative sense of family life, the way every detail of home and connection (even, maybe especially the most frayed of connections) tell the story and make us care about it. A ribbon, a mirror, a boot, a box of family photographs, a Beach Boys song –- the juxtaposition of the ordinary with the unthinkable sustains a “golly” factor that grabs our throats and our hearts at the same time.

The special effects in the movie are dazzling. Just when we thought that we were so accustomed to the limitless wonders of CGI that we could never be stunned in a theater again, Spielberg just plain knocks our socks off. My husband counted eight spontaneous “Oh my Gods” coming from me during the movie. It isn’t just that it all looks real, seamlessly integrating the effects. It’s that what looks so real is so “Oh my God.”

The images are fresh and imaginative and yet perfectly believable, mixing the normal with the inconceivable, from the vast alien machines to the buckling of the earth and the apocalyptic landscapes. The most vivid images are when we see the trappings of everyday life transformed. In one moment of complete insanity, the bells at a railroad crossing start to clang, and the striped barriers come down as though it is a perfectly ordinary day and the commuter train is about to arrive on schedule. Everyone stops and takes a breath and then the train comes in, filled with flames.

Spielberg’s other great trick is his mastery of scale, and again, that use of context brings the story literally home. At least half of the “Oh my Gods” were responses to wow-style reveals of new threats, new invasions.

And Spielberg makes invasion into a theme, from the very beginning, when with stunning economy he sets the stage for all that is to come.

Our hero-to-be, Ray (Tom Cruise) arrives home late. His ex-wife Mary Ann (Miranda Otto), pregnant by her new husband, is standing there with a hand on her hip. The new husband is handsome, a little sleek-looking in a black turtleneck, but clearly so nice you can’t even bring yourself to hate him, though Ray has clearly tried. Even though the ex-wife is late, she decides to carry their daughter’s suitcase into Ray’s house. Ray is very uncomfortable as she opens his all-but-empty refrigerator and peeks into his messy bedroom. He feels invaded. His children seem alien. And yet, in one of the most understated but meaningful moments in the movie, a shared joke between Ray and Mary Ann shows us a glimpse of Ray’s asperity and resolve.

But all of that is under the surface. When we meet him, Ray has long been used to disappointing people. It is not clear which is worse, the sullen animosity of his son Robbie (Ray wears a Yankees baseball cap; Robbie pulls out one with a Red Sox logo) or the patient lack of expectations from his daughter, Rachel (Dakota Fanning). But when it becomes clear that something very, very bad is happening, Ray will do anything to keep his family safe. This will be his story more than it is the story of the battles. The movie is at heart, well, heart.

And Cruise does heart well. He and Fanning anchor the film with outstanding performances of conviction and charisma. Rachel’s protection of her “space” and Ray’s efforts to care for her memory and spirit all echo the invasion theme. The story moves well from the large scale destruction of a city to a small-scale intrusion into a shattered basement retreat occupied by three people. Throughout, the focus is on Spielberg’s favorite subject, the family as fortress. The government barely exists, the army is dedicated and honorable but overmatched.

And, as Ray points out, the humans are almost as dangerous as the aliens. Ray is not the only one who will do anything to keep his family alive and the ochlochratic chaos means that nowhere is safe.

The story is affecting, the action scenes are thrilling, the issues are resonant. Yet it is not ultimately as satisfying as less skillful movies like Independence Day. It may be wiser and it may have more artistic validity, but summer explosion movies call out for a more complete resolution than the Wells book allows. A valid but subtle point is lost, not for lack of respectful presentation, but perhaps because ot it.

Spoilers alert: Parents should know that this is an extremely tense and intense movie, with constant peril and violence. Many characters are killed. Many are neatly vaporized, but there are scenes with dead bodies, a brutal off-camera murder, a death by impalement, guns, grenades, lasers, and other weapons, and some grisly images. Characters use brief strong language. There are tense confrontations between family members. Some viewers will find the behavior of the humans more disturbing than that of the aliens.

Someone once said that the aliens in movies tell us more about what we are thinking about than about any likely real-life extraterrestrials. The UFO movies of the cold war era were, under this analysis, a reflection of our fears about communism and the atomic bomb — with the 1956 version of Invasion of the Body Snatchers and The Day the Earth Stood Still as examples, contrasted with the more benign aliens of Spielberg’s other movies. What does this movie tell us about our current fears?

Families who see this movie should talk about how the story has changed since it was originally written by H.G. Wells more than 100 years ago. How was that era’s interest in the relatively recent scientific discoveries reflected in the book and how has the current version used modern concerns to connect to a contemporary audience? What do you think about the balance of the story between the action and the personal drama as Ray’s character has to become more responsible and
find a way to communicate with his children. How did both parts of the story help each other? In a situation like this, who do you help? Who do you accept help from?

Families who appreciate this film may enjoy listening to the legendary Orson Welles broadcast. This version of the book has the radio script as well. The text is also available online at Project Gutenberg. The new version has a small tribute to the George Pal movie. They will also enjoy Independence Day, one of the all-time best alien invasion movies, and they might get a kick out of Battlefield Earth, one of the worst, and Signs, one that has a bit of both.