MS-54

MS-54 is the school that Percy is attending during The Titan's Curse. It is only briefy mentioned when Percy is telling about the school he is attending in comparasent to the all girl's school Annabeth and Thalia are attending. While it is never officially mentioned, it is assumed that Percy was expelled from this school as well seeing how in The Battle of The Labyrinth he is going to orientation at Goode High School