Heartlight is the fourth contemporary fantasy novel of the Shadow's Gate series by Marion Zimmer Bradley. Co-written by Rosemary Edghill. Although Heartlight is considered to be the fourth book of the Shadow's Gate series, it's partly linked to Marion Zimmer Bradley's Colin McLaren series.
Heartlight is the story of Bradley's greatest champion of good, Colin MacLaren, as he carries the banner of Light through the second half of the twentieth century. Ghostbuster, exorcist, student and teacher of the mystic arts, Colin meets Claire Moffat, who becomes his dearest friend, when he rescues her from a cult bent on human sacrifice.
The leader of that cult, Toller Hasloch, becomes one of Colin's greatest enemies. Working behind the scenes for the next thirty years, Hasloch subtly manipulates politics and the economy to turn America away from the Light. Colin, busy saving lives and teaching the next generation of psychic warriors, realizes almost too late how Hasloch has warped America's promise.
Now, Colin MacLaren is the only one who can face Hasloch and the hellhounds the younger man has unleashed. He must fight on, while the fate of America, and perhaps all mankind, hangs in the balance.