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.
Annie and Tom are pre-occupied with a series of tests they are undergoing to gain acceptance into the student Summer Astronaut Orientation Program, and theyve given Paul permission to use the workshop to find a cure for his incurable hiccups. While Annie and Tom are fulfilling the sleep deprivation part of their testing, Paul sets chemistry in motion and accidentally concocts a dangerous explosive compound!
Annie has her heart set on breaking the 45 year old speed record for tricycles and has enlisted the help of Tom to design and build the record-breaking trike, and none other than Barney Rubberknees Youngfield, the original record holder, as her coach. During Annies training, the team begins to suspect that someone is out to sabotage Annies plans.
Tom and Brain plan to launch a model rocket and they borrow and install a teachers valuable altimeter in the rocket to record the height of their victorious launch. Their troubles multiply on the day of the launch when the rocket veers out of control, gets lost in the forest, and Paul in charge of security claims there are spies in the forest who are after the rocket!