The Headmaster's Run takes readers on the journey of an Illinois high school runner who becomes Ivy League champion and leader of his class at Harvard. As a Marshall Scholar, he continues his academic and athletic pursuits at Oxford and marries the love of his life, Martha, while preparing to become an Episcopal priest. His training takes him and his wife to an Alaskan Indian village and a parish in Spanish Harlem. Mullin then becomes a young chaplain and teacher at the Choate School during the cultural upheaval of the 1960s. In this memoir, the author tells stories from his life and work, including surviving a fatal storm on the Irish Sea, late night faculty parties, and Halloween antics.

Mullin writes of the challenges of becoming headmaster of St. Albans in his thirties, raising three children in Washington, D.C., and attempting to share with his students the ideals of courage and truth. He takes us behind the scenes as he educates the sons of the powerful, counsels a teacher diagnosed with AIDS, and confronts his own controversial departure from St. Albans.
At its heart, The Headmaster's Run is the story of a man committed to education, faith, and family.