On the shore of the blue sea, where a gentle breeze whispers fairy tales and waves dance under the moon, a young couple, Igor and Diana, live in a cozy house. They have everyone's favorite Labrador, Berta, whose tail always wags with inexhaustible optimism.Every day begins with a walk to the sandy shore to swim in the sea and play with the dog.But one day, everyday life fell into an abyss. Literally! A ball, like a naughty rabbit, rolled into a small hole in the ground under an old tree. Without thinking twice, Bertha, driven by curiosity and excitement, dives into this unknown portal, and the girl has to go down there to find her Labrador.And this is where the fun begins! Instead of the familiar sight of an underground tunnel, a fantastic world spreads out before them, where our heroes find themselves in the thick of adventure! Diana and Bertha find new friends and, with their friendship and support, as well as their ingenuity and courage, help the inhabitants of the Lower Level defeat the insidious ruler of the Underworld. After that, they set off again on their journey up to the Middle Level to return home, but that's another story, which will continue the tale of Diana and Bertyona's exciting, magical, interesting, and incredible adventures in the Water World. You will find it in Book 2.