Tilda, Walter, and Fred are now inventors! The soda maker is a brilliant idea from Walter, or at least that's what the three of them think. Until, during their experiments, the roof of the shed flies off and the big guy and the skinny one get blown away. This is reason enough to first install a proper confetti alarm system. When the friends then test their soda maker at the swimming pool, chaos ensues. A delightful summer vacation adventure about outrageous inventions and three inseparable friends.