Look out for ghost goo! Dripping sticky green slime wherever it goes, an “ASG” (that’s Averagely Spooky Ghost) is hiding out in Tom’s cellar. Why? Because it’s being haunted, too—by a much bigger, way badder Incredibly Revolting Ghost (“IRG,” for anyone new to ghouls). And the IRG is the kind of ghost that uses its head—as a ginormous bellowing bowling ball, gross! Good thing for Tom his grandma’s best friend just happens to be a world-famous ghosthunter.