With numbers of new volunteers declining every month, the British government wrestles with the issue of conscription. Across Europe, all the Great Powers are feeling the manpower and other shortages created by the war.

After the overthrow of Victoriano Huerta, the revolutionary forces in Mexico begin fighting among themselves, and Huerta himself conspires with the Germans to return to power.

Albert Einstein needed ten years to flesh out his special theory of relativity into a general theory of relativity, but when he finished, he changed our understanding of the nature of reality itself.