This film takes place six years after a satellite has crashed and brought back a lifeform that's taken over half of Mexico. A journalist, Andrew, is hired to get a rich american tourist, Samantha, out of this infected zone. Basically, he's just doing this for the money but the more time they spend together the more he develops a connection with this "poor rich girl". They pay thousands of dollars to take a ferry out of the zone but that's cancelled because it's too dangerous. The monsters are acting up. And the Americans continue to bomb them in fighter jets so they will not make it past the Mexico/US Border. So Andrew and Samantha must trek through a dangerous part of the infected zone and are led by a ragtag team of hired guards. It's here we learn more about the monsters, how their life begins in the trees and how they eventually make their way to the water where they grow huge. The creatures resembled big octopi. There are some dangers along the way, such as when the group is attacked by a few of them and their vehicles are flipped over. Now alone, the couple has to get to safety by themselves. When they do come to the wall, which was constructed to keep the beasts out, we see that it's massive. And seemingly abandoned. They cross the border into Texas and discover that America has been invaded. They also witness something no one has witnessed before, which totally changes their view about the monsters.
Very laid back giant Monster movie, brings to mind Stephen King's THE MIST more than it does a Godzilla movie. Think of it as the flip side of CLOVERFIELD.