That Hideous Strength is a novel by C. S. Lewis first published in 1945. It is the third in Lewis's theological science fiction series featuring the philologist Ransom, following on from Out of the Silent Planet and Perelandra (a.k.a. Voyage to Venus). In style it can be called a pastiche of the novels of Charles Williams.
This final novel is a parable of good and evil, set in a small English university in which a research agency, N.I.C.E. (National Institute for Coordinated Experiments), is actually a front for Satanic forces. Ransom appears once more in a Christ-like role as the modern inheritor of the role of King Arthur, but by this time has become too uncorrupted to have much effect against such an agency without being himself corrupted. So an older, more ambiguous agent is recruited to the fight: the resurrected wizard Merlin.
