The anomaly is a being from outer space called the Silver Surfer, so named because he's silver, and rides a surfboard like object. A wielder of cosmic energy, he awakens the statue that is Victor Von Doom, who is promptly defeated by the surfer. As Earth begins to mass its forces though, the Fantastic Four are obliged to join forces with Doom to try and defeat the surfer.
It turns out that the Silver Surfer is the herald of an alien being called Galactus, who devours the life energy of worlds. The Surfer sold himself into bondage to save his own planet, and now feeds others to Galactus. However, once Galactus arrives, the Surfer decides to rebel against his master and fights back. The cosmic energy he wields opens a rift, sucking in Galactus and apparently killing the Surfer as well. Reed and Sue are married in Japan, however, when the camera pans in on the Surfer's body floating through space, his eyes open and he summons his board to him, letting the audience know that he is in fact, far from dead.