It was refreshing to see a return to a Sci Fi movie based on suspense rather than horror. It had a decent and plausible story line. It was not heavy on special effects, but those it had were realistic enough not to detract from the movie. The acting was good, and the characters believable. It was unpredictable enough to keep you guessing, but did not have to come from left field to surprise you. The twists made sense within the context of the movie. If you watch Sci Fi for the horror aspect, you won't get much out of this movie. But if you watch for a decent story and a decent movie in a Sci Fi genre, you shouldn't be disappointed.