The Cutie Mark Crusaders are in a dire situation. After trying to help other ponies get their cutie marks (and filling up the hospital in the process), they decide visit Button Mash, only to discover him dead. Apparently the victim of a ritual involving red paint, broken string, and some kind of minty fresh foam oozing from his mouth, he's lying in a heap in his excessively filthy room. Regardless of who did it, his mother is so going to blame them, and she's already promised to kill them if they so much as maim her precious little Button even a little bit.

Can they solve this mystery before she finds out, or will they be competing with each other to see who can push up daisies the fastest?