While Paul is looking after a neighborhood dog, someone manages to steal the dog- The Edisons discover that several neighborhood dogs have been stolen and they organize a search party to recover the stolen pets. Tom and Annie apply their knowledge of sound to construct a parabolic microphone to help them pinpoint the location of the thieves hideout so they can free the dogs.
Paul decides to help Tom out with a geology assignment by buying some rocks for him, but he is accidentally sold some real hot diamonds instead. To retrieve his diamonds, the thief breaks into the workshop later, kidnaps Paul.
While the Edisons investigate a suspicious-looking set of monster footprints, Paul gets spooked and accidentally falls down the bluffs. Tom and Annie apply their knowledge of leverage and gravity to devise a pulley system (Atwoods Pulley) to lower their brother to safety.
Paul decides to borrow a new robot invention of Toms to gain access to a junk yard, but the robot malfunctions and nearly destroys the junkyard. When the yard owner gets trapped under a fallen car, Tom and his robot come to the rescue. Tom explains how his robot functions using the science of feedback.
Tom is saddled with looking after a friends boa constrictor for the weekend. When Paul discovers Toms secret, he and Joey accidentally let the snake out of the bag, so to speak, and a hilarious search begins through the house for the missing snake which the Edisons simultaneously try to help Mom prepare for the evenings dinner party for the Chamber Music Society!
Paul is challenged to spend several hours in the old Murdock house to prove it isnt haunted. Even with Tom and Annie along to keep things scientific, strange sounds and apparitions confront the Edison, convincing Paul that the house really is haunted by a ghost.
With the annual Charity Picnic just a week away, Annie discovers that the local swimming pond is polluted. She meets resistance wherever she takes her evidence, however, as nobody wants the picnic cancelled. The twins, with the help of Paul and Joey, set out to catch the culprit who is dumping toxic chemicals into the pond.
While playing football with his friends, Paul finds a money clip that was dropped by a man he saw stumble past their game. A distinctive logo on the money clip leads Paul to the owner, the head of a large corporation; but when Paul sees the man again, hes convinced the man is not the same man he saw in the park.
The local newspaper is sponsoring an amateur photo contest and Paul decides to enter. When a mysterious unidentified woman takes a serious interest in Pauls photo and negatives, Annie and Tom decide to look deeper into the pictures and investigate.
Paul tried everyones patience as he turns punk-rock guitarist and claims to have picked up transmissions from outer space on his guitar amplifier. When Lances car is stolen, Annie and Tom investigate and discover Pauls space transmissions are more important than they thought.