In his intriguing and unexpected second novel, Biology Professor Matt Ritter delivers a strange and startling generational tale of hardship and triumph in the American West. Natural science blends with history, and an unforeseen chain of causation emerges. In current day Los Angeles, UCLA Professor Marcus Melter is called to the scene of a gruesome murder by his friend, Detective Jack Bratton. While the case leads them into a mysterious world of crime and conspiracy, we learn about the bizarre history of these two men's connected families. Ritter uses his keen natural history observations and unerring sense of place to spin a haunting narrative of intertwined families moving between continents and across the American West, each ultimately affecting the other's path. Marcus and Jack become the axis around which Ritter spins an interconnected story of time, cause and effect, and small random occurrences that create sweeping changes in the world. Earthworms' arboreal genocide, death at the headwaters of the Los Angeles River, the courtship of a hawk, the growth of California walnuts, a mutiny on an 18th-century French warship; all strands of an intricate and convoluted web bridging the gap of time and space. Halo around the Moon is a modern-day-mystery of chance encounters, old family secrets, and a tangled history of coincidental past and present events set in the danger and turmoil of a Los Angeles crime investigation.