The Heaven Makers | Frank Herbert
Immortal aliens have observed Earth for centuries, making full sensory movies of wars, natural disasters, and horrific human activities . . . all to relieve their boredom. When they finally became jaded by ordinary, run-of-the-mill tragedies, they found ways to create their own disasters, just to amuse themselves. However, interfering with human activities was forbidden, and by the time Investigator Kelexel arrived to investigate, things were really getting out of hand. . . .