Time Enough by K. M. Megahee

One day in 1985, Churchie Tyler and Merrie McAllister meet and, later that day, a corporate executive is murdered in his office. These unrelated events set the stage for the events that follow in “Time Enough”. Fifty years later, influential US Senator James Lodge pressures the Historical Event Research Organization (HERO) to investigate his father’s murder, using newly-developed Time Travel technology. Army Ranger Captain Marc McKnight is assigned to travel back in time, witness the event and bring back the story of what really happened. Everything proceeds according to plan until McKnight accidentally interacts with Merrie in 1985, preventing her from meeting her future husband. This alters history and affects the descendants of the Tyler family, including McKnight’s teammate Winston Tyler III. Now, McKnight must repair the damage he caused and complete the original mission. Despite his efforts, he runs into Merrie again, creating more wrinkles in history. Worse, she is beautiful, smart, and full of life – and the one woman he cannot have.