Colonel Frank Underhill has spent his life serving others—his country, his town, and his family. He is a retired Marine, a steady presence, a man whose word has always meant something. When people need help, Frank shows up. He always has. But now his memory is beginning to fail. As the early stages of Alzheimer's quietly take hold, Frank's wife Annie and their sons are forced to face a reality they never planned for. Small moments shift. Familiar routines slip. The house that once felt unshakable begins to change in ways only love can recognize. Set in a small town during the days leading up to Christmas, What the Colonel Built follows a family struggling to protect dignity, routine, and connection as memory begins to unravel. The town that Frank has spent a lifetime supporting slowly steps forward—not out of obligation, but out of respect—for the man who never asked for anything in return. This is not a story about miracles or easy answers. It is a grounded, intimate portrait of family, service, and the quiet courage it takes to stay present when strength fades and time begins to slip.