The book "Prisoners in 'Black Russia': Letters June-November 1915" by Ruth Pearce tells the story of an American nurse and reformer who ended up in Russia during the First World War. The heroine's diaries and letters describe her impressions of the conditions and events surrounding her, caused by the war and the revolution. With unwavering courage and faith in human dignity, Ruth Pearce shared her own observations and impressions with readers, creating a unique document of those times and events. The book is a very valuable source for studying the history of the First World War and life in Russia at the beginning of the 20th century.