At the start of the film, we meet Jack Bruno (Dwayne Johnson, the muscle-bound actor whom I remember most vividly from “The Scorpion King” ), playing a cab driver in Las Vegas. He is picking up and dropping off passengers at Planet Hollywood, where a UFO Convention is taking place. One of his passengers is Dr Alex Friedman (Carla Gugino), “a failed scientist who is giving speeches about legitimate scientific theories of UFOs and outer space” (see IMDB synopsis).
Around the same time, a spaceship suddenly crash-lands on earth, and a government agency under the control of a sour-faced Major Henry Burke (Ciarán Hinds) rushes over to secure the site. They find the spaceship, and evidence that two aliens have survived the crash – and the race to find them is on!
The two aliens have the form of two blond teenagers, Seth (Alexander Ludwig) and Sarah (Anna Sophia Robb – whom I remember from the enchanting children’s fantasy, “Bridge to Terabithia”). They are brother and sister, and have been sent from their home planet to pick up the results from a scientific experiment that their parents conducted on Earth. The atmosphere on their planet has become increasingly toxic and polluted over the years, and so their race has been searching for another planet that might be able to sustain life.
If Sarah and Seth fail to return to their home planet in time with the results of the experiment, which show that the atmosphere can be cleansed, the military powers of their home planet will begin invading Earth. They somehow meet up with Bruno and persuade him to help them fetch the results of the experiment, and to retrieve their space ship from Witch Mountain – all while evading capture by Burke and his team. To complicate matters, they are being pursued by a “Siphon”, an alien creature from their home planet, built to assassinate them and to prevent their return. During their quest, they enlist the help of Dr Friedman and assorted kooks at the UFO Expo.
It was great fun to watch, with the tension of the chase being ratcheted up from one scene to the next. And fortunately the director didn’t give in to the temptation to make it too comedic or the inevitable goodbyes too gooshy (you can see the scenes he shortened among the Deleted Scenes).