Oh dear.

Rating: 1/10 (4 August 2008)

Oh the horror, the unspeakable horror! The Happening is horrible, but not in a good way. There are parts of the movie that are really exciting and intriguing, and M. Night Shyamalan keeps the viewer guessing, as he is wont to do. This is all, however, completely secondary to the unfathomable lameness of the ending (and, to a lesser extent, Zooey Deschanel's atrocious acting).
Spoilers ahead...
People are killing themselves, and the end of the movie gives us the answer to this suicide spree: Plants have "rapidly evolved" in response to humanity's disrespect for the environment, and these plants spend 25 hours pumping out lethal chemicals.
I wish I were making that up, but that's the explanation.
Apart from the obvious (i.e. that this is possibly the lamest, least exciting, and most laughably inane premise for a movie), I am absolutely horrified by M. Night Shyamalan's decision to include not the scientific fact of evolution, but a twisted version which conforms to the Creationist misunderstanding of the term.
Species do not simply make a collective decision to evolve in order to meet a challenge. Animals do not grow extra arms or legs overnight to fight off a competitor. Evolution is not a conscious undertaking, but an unavoidable phenomenon which emerges due to the combination of random genetic mutation in individuals and subsequent non-random selection in the areas of survival and reproduction. I shan't go into further detail since this is a movie site rather than a scientific blog, but suffice it to say that M. Night Shyamalan's understanding of evolution is feeble at best, and, if taken to reflect reality, makes the pro-evolution crowd look like bumbling imbeciles. We are not, I believe, but unless people like M. Night Shyamalan stop propagating these outrageously inaccurate misunderstandings of evolution, we will forever appear as such.
Returning briefly to the other parts of the movie, I suggest anyone interested in watching this car wreck of a film simply stop watching after about 1 hour and 15 minutes. Everything even remotely interesting has already happened at that point.
Pseudo-science, bad acting and inane storytelling earns a score of 1/10.