If it helps, rumor has it that originally the base game was to include three timeline/adventures. The production version cut back to just "Asylum". "The Marcy Case" and "Under the Mask" were released as separately purchased expansions.
Odd, I heard just the opposite, that originally it wasn't going to include any stories at all, just the base system. Then they thought it might be a bad idea to sell a box that couldn't be played by itself so they decided to include Asylum.