Two boys are found disrobed with fatal gunshots in their school on a Saturday. Benson and Stabler believe a third boy was held hostage, but further investigation shows he was the killer pretending to be a victim. The boy's mother claims the drugs he was taking for his depression were the cause of his manic behavior. Cabot goes ahead with the prosecution, but soon learns the drugs were never prescribed. Instead, they were mailed from a pharmaceutical company as a sample.