"Heikki Helmikangas" is a book written by the author of Sissala, Eero, which tells the story of an unusual aircraft capable of performing impossible maneuvers in the air. The main character, pilot Heikki Helmikangas, strives to reach exceptional heights in his career, but he will have to go through tests that will break his notions of reality and the limits of what is possible. This exciting book about adventure, faith and courage will captivate the reader from the first pages and leave a generous supply of ideas.