Nothing happens in Aslyum's plot that's noteworthy. It's really the most straightforward insane asylum takeover story, doesn't explore any interesting themes and has such a cop out ending. It bypasses the actually interesting story bit (
) by making it an optional discovery and doesn't tie it into the main game. Titan crap sucked, boss encounters were lame both gameplaywise and a bit lame thematically.
An interesting Arkham story is A Serious House on Serious Earth. I'd bet any other comic about Arkham would be more interesting plotwise by default considering they don't have interactivity as a main draw and being visually entertaining only goes so far.