This book is the third in a series that summarizes World War I for general readers. The author’s first two books—Explosion and Roll of the Dice—respectively covered the events leading to the war’s outbreak and the conflict’s first four months (August to November 1914). Walls Closing In addresses the period of December 1914 to April 1915. The book’s principal emphasis is on the war efforts of Germany and Austria-Hungary, the two nations’ struggle to withstand the overwhelming combined power of the British-French-Russian alliance, and the deterioration of the Central Powers’ strategic and diplomatic situation in early 1915.