David is looking forward to spending another adventure-filled summer at his grandmother's Intergalactic Bed & Breakfast-a vacation hotspot for aliens. But as soon as he meets Grandma's new repairman, an alien named Scratchull, he becoms suspicious. The only problem is that it is difficult to be sneaky when you have a ravenous alien pet attached to you. Even though no one else-including Grandma-thinks that Scratchull is an underhanded handyman, David decides to spy on him. But no one believes David when he discovers that Scratchull really is an evil mastermind with a plot to destroy the planet. Without the help of Grandma and his friends, will David be able to save Earth before it's too late?