Dwayne Johnson plays Jack Bruno, Las Vegas cabbie, and Carla Gugino is Dr. Alex Friedman, UFO expert. Perhaps you saw the preview in which Bruno and Friedman are crawling thru a tubular tunnel and she admits to a bit of claustrophobia. Just then Bruno reaches an opening into a deep vertical shaft and asks "How are you with heights?". It was a good scene, with a bit of low-key but contextually appropriate humor that the former Rock has learned to deliver effectively, making him a big, strapping brute of a guy that you feel comfortable with. But that scene isn't in the film itself. Instead, we see the aftermath, in which Friedman is still a bit freaked out, for no apparent reason.
The rest of the movie was like that, too. People seemed to be doing things with no credible motives. The 2 adults flee from no fewer than 4 sets of pursuers exhibiting varying degrees of hostility (The Government, a space-alien cross between Predator and Inspector Javert, Bruno's former mob boss Mr. Wolf and his henchthugs, and the LVPD). They do so to protect 2 teenage Swedish, I mean space, aliens who are here to retrieve the mcguffin, um, recording device that will prevent their planet from launching a hostile takeover, uh, invasion. The gal of the pair, Sara, is played by AnnaSophia Robb. We know from her performance in Bridge to Terabithia (2007, 9*) that she can be a tremendously appealing young actress, but here she gets to do stuff like pointing her finger and monotonically saying "Go that way, Jack Bruno.". The boy, Seth, is played by Alexander Ludwig, a cipher.
The government's head alien tracker warns Bruno that the kids are not what they seem to be. Anyone who's ever seen a science-fiction movie (which apparently includes precisely zero of any characters who are actually IN an SF movie) can only begin to imagine what might lurk beneath those placid blond exteriors, but this proves singularly untroubling for Bruno, leading right up to the snuggle-bunny ending (Disney, y'know), which was likewise not well set up by any of the preceding events.
The scenes set at a UFO convention make good sport of fannish stereotypes, which some people might find offensive but I choose to treat as endearing. And I loved the sly humor that they DID leave in the script, wherein Bruno asks the kids at the controls of the flying saucer "Do you know how to fly this thing?", they respond "How do you think we got here?", and he replies "Well, you crashed!". More of that, from another couple of passes thru the typer, would have earned this one an upgrade.
*Best SF&F film of the 21st Century so far, IMHO
