[quote name='willardhaven']Can someone give me a slightly brief, albeit detailed summary of what happened in Chain of Memories?
The FAQ I read was so convoluted that I could barely get the basic characters in order, although it seems like there were a lot of new ones introduced.[/QUOTE]
CoM story was pretty odd, but I'll try to remember what happened:
Sora Donald & Goofy walk into a tower looking for Riku and the King. While going up the tower they start losing their memories of friends, (like Alladin, Jack etc.) The further they go the more memories they lose, he eventually forgets Riku and Kairi.
A girl named Nanamie (The girl who draws) is drawing the floors of the tower from Sora's memories, from the places he's been in the past, like Agrabah, and such. So he ends up meeting with his old friends again, but they're not real, only visions from his memory.
Also along the way you meet up with members of Orginization XIII and end up defeating, I think 7 or 8 of the members. They never do find Riku or the King, but at the top he finds Nanamie. She tells him in order to regain his lost memories he has to sleep in some bubble for a while. So he sleeps, but when he wakes up he seems to have forgotten about the tower and Nanamie. Nanamie is good and is only helping the Orginization cause they're using her. They also meet Dizz, I forgot what he said, to them, but I remember him helping Sora. Don't know why yet.
Riku on the other hand fights his way up after Sora. He meets up with the King and he helps him. At the end Riku defeats an image of Ansem. After he wins he relizes he is neither totally light or dark, he's "in between. which makes him unique" Riku finds Sora sleeping in his bubble then decides to go of with the King to do stuff.
Hope that helps, it's been a while since I played, so things might be a little off, but generally that's what happened.