As Cook makes clear in his introduction, it is not an exhaustive look at Canada during the war. It solely focuses on the Canadian Corps, the army faction that fought; there is nothing about the air corps, navy, home front, and aside from brief mentions of Sam Hughes (minister of militia until 1916), no political details. As the title states, it starts from the Canadian entry into the war alongside the UK in 1914, and ends with the conclusion of the Battle of the Somme in October 1916.
The writing is very clear and straight-forward, and makes great use of quotations from memoirs and letters from soldiers at the front. Cook does a good job to present the horrors that the soldiers had to face, making constant references to the conditions of the trenches, often noting the presence of decaying bodies and human remains scattered about. Naturally, the artillery that characterised the front is also detailed, sometimes preceding the mention of the dead and wounded.
The individual is a constant theme throughout the book. As Cook makes heavy use of soldier's writings, he focuses on them at times; for example, in several instances he will go to lengths detailing how various soldiers acted during a battle, giving the reader a close-up perspective on how it felt. This has a certain effect, amplified as some of these accounts are closed by the somber note that the soldier was later wounded or, quite often, killed later on. Though Cook focuses on the front-line soldiers, he also takes time to detail the officer corps, noting the political aspects that gripped the leadership of the Canadian military to some extent.
Though heavily focused on the battles the Canadians took part in (Second Ypres, St. Julien, Festubert, Somme, to name some), Cook also spends a good amount detailing the other aspects of the war. Chapters explaining the construction and maintenance of the trench system, the rotation of units, their training, and the medical system are just some of the topics covered, giving a more rounded and nuanced impression of life for the soldiers.