The residents of the Canterlot Prison have reason to be terrified when the sun goes down. What terrors patrol the Canterlot Prisons late at night? And more importantly, what does he want?

Ditzy, aka Derpy, is no stranger to being bullied and expects to be by anypony she meets. But Ditzy is about to find out that not everypony you meet is a bully, and help and understanding can come from the most unexpected of sources.