Which C.S. Lewis novel concludes his Ransom Trilogy?

That Hideous Strength concludes C.S. Lewis’s Ransom Trilogy.

The trilogy begins with Out of the Silent Planet, published in 1938, and continues with Perelandra, published in 1943. That Hideous Strength followed in 1945 and shifts much of its setting from other planets to England. The central academic and supernatural conflict involves the National Institute of Coordinated Experiments, known as N.I.C.E.

The books are linked by the character Elwin Ransom, who becomes a central figure in Lewis’s imaginative treatment of science, morality, and cosmic conflict. That Hideous Strength also draws on themes associated with Arthurian legend and medieval Christian thought.

Although the three novels form a connected sequence, they are not usually grouped with The Chronicles of Narnia. The Ransom Trilogy is also called Lewis’s Space Trilogy, even though the final installment is largely set on Earth.