Guys, Tilda's grandma needs our help! She is determined to win the competition of the community gardening club. Unfortunately, she has absolutely no clue about plants. And of all people, the Klose brothers are her competitors! Of course, they are using really nasty tricks. So, we need a super fertilizer. It's a clear case for us inventors! But who would have thought: in the end, we actually find ourselves right in the middle of the jungle. I hope this goes well... The fourth adventure of Fred and his inventor friends includes everything that excites children: suspense, humor, fast pace, and quirky illustrations!.