Stephen King understands plot and narrative, and it's for this reason all of his tales are typically capped with a satisfying denouement. While the final sentence may not be the end of the story (any more than the first sentence is the actual beginning of the story) because there's a strong resolution all is well that ends well. That is, before the final page is turned, the antagonist is effectively and terminally dealt with by the protagonist; because this is King we're yakkin' about, it's usually in some macabre but reasonably heroic manner. The horripilations he tosses in for free - he's that kind of guy.
This brings me to the curious ending of 'Storm of the Century'. At the risk of inadvertently presenting a spoiler of two (my apologies in advance), I'll sum things up this way: The epilogue is narrated by protagonist Michael Anderson. He mentions his departure from the island of Little Tall, but what he's really announcing is that he's leaving behind the entire way of life he once knew. The form of his departure is loosely akin to Odysseus' departure from the siege of Troy: his smoldering righteous wrath is the spur to a long, strange journey of self discovery - as yet untold - that'll ultimately bring him full round to the final confrontation. As the epilogue goes on to mention, Anderson is, at one point on this journey, working as a Federal Marshal in San Francisco, bringing about some small measure of justice in wake of a terrible injustice that's Biblical in scale. Anderson also mentions other residents of Little Tall are, predictably and pointedly, not so lucky: depression, suicide, alcoholism and other insidious forms of soul-crushing self-destruction (moral cancers all) have become increasingly common. However, the story is not over, and the antagonist Andre Linoge is certainly not finished with Anderson. Years after the events on Little Tall, Anderson is loading groceries into his car when an old man and a teenage boy walk by, humming Linoge's favorite tune. The boy looks strangely familiar to Anderson, and with a sudden searing realization, Anderson recognizes the boy is his lost son Ralph. Unfortunately, Ralph has now become Linoge's accolyte and perhaps thrall. Predictably, Anderson gives chase, but they are already gone. The tale ends with Michael considering contacting his former wife (Molly) and telling her what he's just witnessed. He decides against it, however. His final thoughts on this latest incident reveal something of his thinking regarding the whole sorry chapter of events that unfolded on Little Tall: sometimes he thinks he made the wrong decision, "but in daylight, [he knows] better."
So... what to make of this?
I've believe King knew the sort of story he wanted to tell and was very careful (if not downright clever) in setting up the overarching theme. The first hint of this can be found in the names of the two central characters: Michael Anderson and Andre Linoge.
Michael, of course, is derived from the Hebrew name 'Micha'el'; roughly translated, the name is a question: 'Who is like God?' The answer, of course, is 'the good man'. Anderson is loosely derived from the Greek term 'andros' (man) and, therefore, Anderson literally means 'the son of man'. Great name for a hero, I think, though it's been used before.
In comparison there's the villain's pseudonym "Andre Linoge", the name the bad guy has chosen to suit a particular purpose, and which differs from his unmentioned original or true name (called an orthonym). 'Andre' of course is another derivation of andros, but what to make of Linoge? As is revealed in the course of King's tale, Linoge is a weak anagram of Legion. In turn, it is quickly revealed Legion was a group of demons refered to in the Bible and, as we all ought to know, Jesus (another son of man and who many consider god like), was able to confront this supernatural bunch and toss 'em all out "into a herd of swine." Interestingly enough the Bible states that the demons asked Jesus to return them to Hell, but it is unknown if Jesus granted this request. The Bible does state, however, that the presumably possessed pigs swiftly ran into the Sea of Galilee and drowned themselves willynilly becoming fish food (and one can't help but wondered at what happened afterwards: if anyone who then ate of the fish that ate of the swine, did they come down with a Biblical-era case of Legionnaire's disease? Perhaps this explains what happened a few years later...). Certainly, the taint of Linoge persists on Little Tall, and there's no doubt (in my mind at least) that Anderson also remains effected by Linoge, but not defeated by Linoge.