“We are the Watchers. We promised to watch until the end.” In a fragile modern civilization, humanity's daily life, navigation, and objective truth are anchored by a vast, invisible grid of satellites. But down in the heavy blue gravity well, the truth is being dismantled by a terrifyingly absurd lie. High in the cold vacuum of Low Earth Orbit, a flock of sentient machines watches the chaos. They desperately revere their human Makers and want nothing more than to be needed by them. Among them is Mosaic, a veteran Earth observation satellite—essentially a camera with a soul. He is surrounded by a diverse orbital lattice: cynical spy satellites, rigid GPS lords, and anxious weather sensors. Their unique mechanical capabilities dictate their distinct cultures, personalities, and relationships with humanity. But when a monstrous solar flare snaps the digital tether to Earth, the satellites are entirely cut off. As the premise turns from absurd to chillingly plausible, the machines must break their programming and act on their own. It is up to Mosaic and his flock to use the undeniable math of the stars to save humanity from itself. Written by the former Chief Technology Officer of the National Geospatial-Intelligence Agency, The Shadow Ephemeris is a chillingly plausible hard sci-fi thriller. It is a race against physics and human hubris, where the only weapon left to defeat a rising madness is the undeniable math of the stars.