What is the main conflict in Ubik by Philip K. Dick?

Ubik is a science fiction novel written by Philip K. Dick. It follows the story of Joe Chip, a technician at Runciter Associates. When an explosion kills Joe Chip's boss, Glen Runciter, strange things begin to happen. Soon Joe realizes his boss did not die in the explosion, but he is in a state of half-life. If he wants to stay that way, he has to keep the evil Jory from eating his life energy.