Some doors were never meant to be opened.
After collecting another missing assignment, thirteen-year-old Troy "Skidmark" Stevenson lands himself in detention for the rest of the year. No more bullies, no more classwork, no more lectures. Sounds like a sweet deal, right? Wrong. Troy becomes Mr. Brenneman's slave, running errands for the lazy detention teacher. Honestly, he wouldn't mind so much if every errand ended somewhere other than the school's basement. Underground, dark, and colder than you-know-where? No, thank you.
While sifting through the basement's junk, Troy uncovers a locked door. Forced to enlist the skills of the school's most intimidating bully, Christina Rainier, he orchestrates an elaborate scheme to pinch the principal's keys. The plan succeeds, and the pair opens the locked door, only to reveal a small room. An empty room.
That's when things get weird. Troy starts hearing voices and seeing things that couldn't possibly be real, and the same string of numbers--1211986--keeps popping up everywhere he goes. Together, he and Christina, the world's most unlikely duo, must figure out what the numbers mean or learn the hard way why someone went through so much trouble to lock the door to an empty room. Or maybe the room was never empty at all?