Shards.

Mercedes has always found escape from the tedium of daily life in fantasy books and, especially, in games, where she can enter another world and become Ambrosia the Sorceress, wielder of powerful spells. After one too many afternoons in detention, she returns home to find that someone has left a new computer adventure game in her mailbox. Mercy and her reluctant friend Bernard take an unauthorized day off to try it out, only to discover that they have literally left their mundane world behind and entered a realm of elves and dwarves and stranger things. Forced into a quest to recover a powerful magical artifact, they soon learn that they're not the only ones seeking the prize, and that -- when you can't set the keyboard aside and walk away -- a game is no longer a game. Instead, it's something like life.