You carefully lift the lid of the trash can. It smells like old banana peels and pencil shavings. You rummage through the paper, trying not to touch anything gross. Near the bottom, you find an empty, squished-up metal tube. It used to hold bright red food coloring! The kind they use for frosting. The frosting is coating the bottom of the trash can. You show it to Ms. Lily. "Aha!" she cries. "The thief must have wanted to add more frosting to the cupcakes they stole." Ms. Lily calls the janitor and asks him to bring a new can. The class garbage bin will need to be cleaned of the sticky frosting mess. She decides that the evidence is all gone, and the mystery is over. No need to have it ruin the party. She serves everyone plain vanilla cookies she found in the bottom of her drawer. They are okay, but they are not the perfect Valentine Cupcakes. The End.