Eight-year-old Jonas travels to the North Sea to visit his sister Sabine, who is doing an internship at the seal rehabilitation center in Norden-Norddeich. During an outing to the island of Juist, they discover a crowd on the beach gathered around a seal pup. The mother seal is hesitant to approach her young one and eventually leaves it. Jonas and Sabine take the pup to the rehabilitation center, as it can only survive with human assistance now. There, Jonas wants to take care of "his" seal pup – after all, he found it! However, like all other visitors, he can only observe the pup through a glass. Gradually, Jonas understands that the seals in the rehabilitation center are being prepared for their future life in the wild and therefore should have as little human contact as possible. At least Jonas is allowed to become the pup's sponsor.