An intergalactic vessel has to make an emergency landing high in the mountains of Colorado. A number of Sentinels are sent out to protect the perimeter. The Sentinel is an intelligence-gathering device grown for this purpose.  It stands up right on powerful legs and clawed feet. Its upper body is humanoid. Its eyes reflect its true nature.

One of the Sentinels has an accident that tears its comunications device away. The electrical shock renders it unconscious. Being an older generation, it has been slated to be recycled. This being the case, the device is detonated. The devce is far enough away to leave the Sentinel unharmed. The next morning it comes to and returns to the landing site. They will not be back.

The forest service begins to investigate sighting, and when alien DNA shows up in a federal lab matching samples from years earlier, the government decides to throw a net over it.

Elizabeth Claywell is a blind, thirteen-year-old girl spending her summer vacation with her family in those same mountains. Elizabeth, while riding with another guest, is nearly killed when their horses are spooked by a rattlesnake. The guest horse runs away with its rider and Elizabeth is thrown from hers. The Sentinel prevents her death.

With several factions looking for the Sentinel and the child, a confrontation is brewing on top of the mountain. The first time it encountered humans it was shot. Because of the nature of its design small arms fire can't harm it. And then after witnessing an act of cruelty against a helpless animal it decides that humanity doesn't have much going for it until it meets Elizabeth someone who doesn't judge by what she might have seen, but by what she feels inside.

The Sentinel doesn’t know the good guys from the bad guys. What it does know is nothing is going to harm its small, human charge. Nothing...