Two children, Apostolis and Giovan, undertake to help the Greek guerrilla forces capture Lake Giannitsa, a region of strategic importance for the course of the confrontation between Greeks and Bulgarians during the Macedonian Struggle. As the actions of the Greek fighters unfold in the inhospitable waters of the Marsh and the neighboring villages, and while we mainly follow the actions of the forces of Captain Agra and Captain Nikiforos, alongside the agony of war, heroism, patriotism, humanity, and faith in hope are also highlighted. One of Penelope S. Delta's masterpiece books with a historical background that has nurtured generations of Greeks and continues to inspire and excite its readers to this day. The book is accompanied by an Appendix with the necessary material for the educational utilization of the work according to the teaching objectives set by the New Curriculum for the teaching of Literature in Compulsory Education - Historical context-period - Pragmatic comments, cultural elements - Ideological axes - Character sketches - Topics for discussion - Suggestions for interdisciplinary projects - project plans. Also, the appendix provides a detailed Chronology of the life and work of Penelope Delta.