ending of silent hill?

There are basically three dimensions stemming from the three different sides of Alessa: Alessa (the original girl and burn victim), Sharon (manifestation of the good left in Alessa), and Dark Alessa (manifestation of the evil in Alessa).

The two “evil” pieces of Alessa could not teach the cultists a lesson, so they reach out to Sharon and set in motion a huge plan. You may remember earlier in the movie, when Rose actually meets with Alessa, that she says Rose will have to make a choice. She made a deal to help Alessa exact revenge on the people of Silent Hill (who were already dead, but still hanging on through their “blind conviction” ) by combining with Dark Alessa to gain entry to the church and essentially, save Sharon.

The plan works, and you see Alessa make her way towards Sharon in one of the final scenes of the slaying in the church where she recombines to create a “reborn” Alessa. Using the knowledge Sharon has of the outside world, Alessa can continue extending the foggy Silent Hill dimension while remodeling it to look like the one Sharon and Rose previously lived in (because Alessa views the real world as a place where she’s been mutilated and abused, and therefore purely evil and bad). You may also remember the quote “mother is God in the eyes of a child”; this also gives a sort of foreshadowing of Alessa’s intentions. Since she was never loved by her mother in the real world, or by the world itself, she sees with envy the love Rose has for Sharon. Because Alessa merges with Sharon, Rose can’t see (or maybe doesn’t care) and continues to treat Sharon as her daughter. This allows Alessa to live her life happy with a mother that cares for her, in a safe world she’s created. However, this indefinitely leaves Rose trapped in an alternate dimension, isolated away from the real world and Chris.

Ideally, this has paved the way for the sequel. If you’ve played the second SH game, the plot basically is centered around a man named James who gets a note from his wife (who is supposedly dead) claiming she’s waiting for him in Silent Hill. I have a feeling this will be shown in the next movie, where Chris might get a letter from either Sharon or Rose dragging him back to Silent hill.