A young teenager named Ray is left at home to watch the family dog, Harry, to prove to his parents that he is not, as they say, "irresponsible". But, before he knows it, curious Harry runs out the front door and into Krepner's house- Ray's kooky, suspicious neighbour. While in the house, he is accidentally doused with a stolen top-secret invisibility formula and then runs wild throughout their small town unseen causing a ruckus. Krepner is ordered to catch Harry to retrieve what's left of the formula in his DNA. Ray and his friends must find Harry before the villainous scientists and FBI Agents get to him first. And before Ray's parents get home!