'Joshua Jones has no one in the world except for a fruit loop of a gran and they live in a tiny city flat so he can't even have a pet. When a spectacular creature on a seven-day visit from Jupiter offers to be his houseguest during its Earth stay, Josh thinks his luck has changed. His nothing life is about to become awesome. His celestial visitor eats frozen peas and crossword puzzles, answers questions with questions and is invisible to everyone except him. That should have warned Josh to expect the unexpected. But soon Traveller will be gone and Josh's life will be back the way it was ... or will it?'
Source: Publilsher's blurb.