Basia Wróbel had two certainties: the best collection of funny erasers in the class and an unbridled imagination. Filip Grzelak could fix anything, even the remote control for the school projector (although now he only skipped to the channel with the snail cartoons). Olgierd Witek, on the other hand, loved to draw technical diagrams even in the margins of his biology notebooks. The three of them, completely by chance, decided one Monday to turn the boring Room 23 into the headquarters of the School's Unusual Inventions Club (SKNW for short). Basia unfolded a colourful shoebox, Filip brought a set of screws and springs from nowhere, and Olgierd put his latest drawing in front of them: the "Automatic Homework Maker". The device had tiny handles for sticking grade stickers, warning lights and - here Basia was already laughing - a lever with the words 'Failure? Kick here." The action was on! First they invented a turbo-lunette from a crisp box. Unfortunately, Philip only saw through it that Jerzyk from 4B was just eating his sandwich. Then Olgierd constructed an Automatic Parallelogram Solver, which (due to a little mix-up with the cables) started shining a pink light on the ears of anyone who approached the board.... Everything was going fantastically until Ms Jola - the janitor known for her ability to find a jelly bear even in the deepest recess of a child's backpack - turned up. She was drawn into the room by complete coincidence when Basia tried to set the turbo-lunette on a drinking straw wrapper. Mrs Jola looked up from her seat and sighed: - What exploded this time? Just then, a suspicious buzzing sounded from behind the wardrobe and the door of the utensils cupboard slowly opened... A small yellow helicopter made of ice-cream sticks flew out through the gap. It flapped its wings like crazy, and on its deck sat a strange, plush frog wearing a helmet made from a milk cap. Philip groaned: - Oh no... I think that's our prototype self-flying sandwich feeder! The frog looked at them defiantly. The helicopter began to lower its flight over everyone's heads, and Mrs Jola closed her eyes and whispered: - 'Just hope it doesn't fly into the staff room...'. Just then the helicopter dived quickly towards the ajar door to the corridor. Basia rushed to catch it, Filip was already pulling out a screwdriver and Olgierd was panicking about whether the frog had accidentally clicked the red 'Start Mission' button. What happened next exceeded their wildest expectations....