The Kraken Wakes

Strange fireballs race through the sky and then dive into the deepest trenches of the oceans. Suddenly, ships are sinking for no apparent reason, carrying hundreds to a dark underwater grave. This, it turns out, is the beginning stages of an invasion of aquatic aliens, resembling a hideous hybrid of jellyfish, octopuses, and crabs, who are planning to take over the world by sinking the continents and flooding the world.