Something mysterious is happening to Felix Spark's house. The upstairs has become the downstairs, the downstairs has become the basement, and Dad's Harley Davidson has been swallowed up by the back lawn. Now there's a huge hole under the house. At least that gives Felix's band, Echidna, somewhere to practise.
But underground is the worst place to be. There's something under there, something threatening to destroy the world . . .
