The Black Echo introduces Harry Bosch, an LAPD homicide detective known for his tenacity and moral code. Called to the scene of what seems like a drug overdose in a drainage tunnel, Bosch quickly suspects there is more to the case than meets the eye—especially when he recognizes the victim as someone he served with in Vietnam, a fellow “tunnel rat.” Pursuing justice becomes personal, and Bosch must navigate a web of danger, deception, and institutional obstacles to uncover the truth.