This is the inspiring story of the first American team to win the Stanley Cup, with six new chapters on their pursuit to become one of sports' first dynasties. In the winter of 1917, as Europe spiraled rapidly out of control and pulled the U.S. into the greatest conflict the world had ever seen, a talented band of athletes in the Pacific Northwest fought to turn themselves into an elite team. That elite team would battle the looming war, their own insecurities, and fierce opponents on both coasts of Canada to captivate a community and journey toward hockey immortality. When It Mattered Most breathes life into the humanity and times of a remarkable team during a monumental three-and-a-half-year period of world history, inspiring readers with a never-before-seen look into the evolution of Hall of Fame players, an improbable championship team, a war largely overshadowed by its second incarnation, and the twentieth centuries' deadliest scourge - the Spanish Flu pandemic.