That Hideous Strength (Space Trilogy Series #3)
by C.S. Lewis
In That Hideous Strength, the final installment of the Space Trilogy, the dark forces that have been repulsed in Out of the Silent Planet and Perelandra are massed for an assault on the planet Earth itself. Word is on the wind that the mighty wizard Merlin has come back to the land of the living after many centuries, holding the key to ultimate power for the force that can find him and bend him to its will. A sinister technocratic organization that is gaining force throughout England, N.I.C.E. (the National Institute of Coordinated Experiments), secretly controlled by humanity's mortal enemies, plans to use Merlin in their plot to "recondition" society. Dr. Ransom forms a countervailing group, Logres, in opposition, and the two groups struggle to a climactic resolution that brings the Space Trilogy to a magnificent, crashing close.