School's back in session and this term, classes at Grisley Manor include Eyeball Extraction, Nightmare Execution, and Advanced Grave Digging. There's a guillotine in the playground and the teachers are literally dying to meet their students.

When Tom and Pete stumble upon a thunderstorm grave-crawl and a talking pit in the cellar known as the Mouth of Hell, they realize something far worse than bad grades is brewing. The staff are long-dead asylum inmates, the townspeople are vanishing, and the school is summoning students at midnight.

Together with the ever-grumpy Mr Block, Tom and Pete must silence the Mouth, outwit a doppelgänger army and survive nightmare-fueled chaos before Little Cemetery becomes a ghost town.... permanently.

Grisley Manor is open, the dead are restless, and detention is forever.