Old and new secrets occupy the children of the tree house. I have to do it. The children of the tree house go out once again to reveal the truth. Will they be able to overcome the heartless crooks? Will they find out why Yoab behaves in such a different way? The children's project of Yaya's tree house (the snake fish) and Ran Cohen Aharonov has in a short time become a unique phenomenon in the Israeli culture for children. I have to do it. The show, the musical albums and the show with the best musicians in the country were praised; And the television series won the Academy Awards for television and millions of views on YouTube. The Secret of Saba Ephraim, the fifth book in the series, is also accompanied by the illustrations of Yaniv Shimoni, one of the leading illustrators in Israel.