The eternally disheveled boy Alva is heading for the third grade with his unique inventions! He arrives with his friends Denisa and Filip on a specially modified motorcycle straight from the veterans race. And that's just the beginning. The trio goes camping in the forest and almost scares the woodcutter to death, they catch thieves in the gallery and save the skeleton Emil in the school office. In addition to the enthusiasm with which our heroes throw themselves into each adventure, they always have Alva's latest discoveries and enhancements on hand. After all, every technical innovation must first be tested, so this time they will ride a special cart through the castle of horrors, try running with a behemoth and digging an underground tunnel with a robo-mole. Each chapter is accompanied by a detailed description of the invention and a bonus comic. New events that you don't know from the evening news!