The sentinels are disappearing.Earth is losing its protectors ...There were no more alien invasions, no crime, or shortages of food and shelter. All was at rest. Until the Cascade began to fall from the sky.Kierkad and his brother Sentinels are ready to die for the Noble Call of protecting humanity. They gave up everything, their home world, their identity, and all memory of the past for the privilege.The Cascade, a virus guided by sentient thought with dread purpose, is designed to make the Sentinels disappear, and as their numbers decrease, Kierkad's world is fracturing. Nothing is what it seems.The Noble Call has become a trap.