Medical errors both in the U.S. and worldwide occur at alarming rates. In the U.S. medical errors were the third leading cause of death. Southwick experienced the consequences of preventable medical errors firsthand. As a physician and a professor, he researched and wrote about the causes and solutions for medical errors over the years. Southwick also launched pilot programs applying different quality improvement frameworks from other fields to medicine. Although the results were positive, he encountered resistance from many physicians. To build more skills, Southwick became an Advanced Leadership Fellow in 2010 and a Senior Advanced Leadership Fellow in 2011. He used his time at Harvard to develop solutions that would address the root causes of medical errors. The complexities in healthcare and the entrenched cultural norms presented strong barriers to creating change. The case explores Southwick's efforts in getting medical professionals to work collaboratively, communicate effectively, and create a new sustainable culture that improves healthcare outcomes. Southwick's experience raises the question of how one person can best make a difference in a large, complex, entrenched system.