A bullied teen stumbles into possession of a top-secret government formula that turns his dog invisible and gives it the power of speech in this zany comedy for the entire family. When Chad Sheppard receives a science kit for his 13th birthday, his dog Abner takes a whiff and starts talking. Later, when Abner turns invisible, too, Chad attempts to solve the problem while contending with a pair of neighborhood bullies conspiring to make him look like a weakling in front of his pretty neighbor Sophie. Now, a shady government employee has recruited a pair of burglars to snatch the dog, and discover his secrets. But these bumbling dognappers are no match for Abner and Chad, and once the chase is on, the real fun begins.