Now You See Him, Now You Don’t

Dexter and friends secretly listen as Dean Higgins updates the board about looming budget shortfalls at Medfield College. The stakes are high because the college could lose funding unless a solution is found. The tension sets the backdrop for Dexter's later inventions becoming a potential lifeline.

Dexter demonstrates an invisibility experiment to Professor Lufkin. A thunderstorm strikes that night, damaging the equipment and foreshadowing trouble. The next day Dexter discovers part of his glasses becomes invisible and realizes the substance renders items temporarily invisible when rinsed with water.

The test confirms that the formula renders objects temporarily invisible and that water rinses the effect away. Dexter confirms the phenomenon with visible evidence and begins to see real potential. The discovery marks a turning point toward practical use, not just curiosity.

Dean Higgins introduces A.J. Arno, a recently released criminal who now owns Medfield's mortgage. Two years earlier, Dexter helped expose Arno's gambling scheme, making Arno's return feel personal. Dexter and Schuyler become wary of Arno's true intentions.

Dexter and Schuyler use the invisibility formula to sneak into Arno's office and uncover documents proving that gambling is legal on college land due to a 1912 statute. They also learn that Arno plans to turn Medfield into a gambling town. The stakes rise as the plot becomes more personal.

Dexter suggests using invisibility to win prize money in the Forsythe science contest. Professor Higgins dismisses the idea, preferring Druffle's bee study, and Medfield has actually been dropped from the contest. The team needs a new angle to save the program.

Higgins meets contest sponsor Timothy Forsythe for golf to gain support. Dexter hides invisibly and manipulates Higgins' shots, delivering hole-in-ones that impress Forsythe. Forsythe agrees to let Medfield re-enter the contest.

Arno spots Dexter becoming visible in the showers and grows suspicious of the invisibility scheme. He starts watching Dexter more closely as the contest approaches. Tension builds as the secret may be at risk of exposure.

Druffle is heavily bandaged after a bee attack, forcing a shift in experiments. Lufkin suggests giving Dexter's invisibility formula a chance, and Higgins reluctantly agrees. The team prepares for a potential breakthrough under new circumstances.

Arno's chauffeur Cookie, disguised as a janitor, spies on Dexter and steals the invisibility formula. Dexter's Forsythe demonstration uses the switched, ineffective spray and the team is embarrassed as they lose their shot. The setback deepens the crisis for Medfield.

Dexter plants a walkie-talkie in Arno’s office and Schuyler overhears plans for an invisible bank heist. They bring the information to the police, but they are dismissed as pranks. The plan looms over Medfield as the criminals prepare to act.

Arno and Cookie attempt the invisible bank heist but Dexter and friends intervene. A chaotic car chase ends when they force Arno's invisible car into a swimming pool, making everyone visible and leading to arrests. The criminals are finally stopped.

The team rushes to the Forsythe Award ceremony for a second chance. Dexter's invisible spray is used again and, during the demonstration, Higgins unexpectedly becomes partially invisible. The crowd gasps as the line between illusion and reality blurs.

Despite the setback, Medfield wins the $50,000 Forsythe Prize to keep the college afloat for another year. Dexter and friends celebrate, and the science they nurtured promises a brighter future for Medfield's students. The film ends with renewed hope for the lab and campus.