How many novels make up C.S. Lewis’s Ransom Trilogy?

C.S. Lewis’s Ransom Trilogy consists of three novels. The series follows the philologist Elwin Ransom through encounters involving Earth, Mars, and Venus, while combining science fiction with theological and philosophical speculation.

The three books are Out of the Silent Planet, Perelandra, and That Hideous Strength. They were published in 1938, 1943, and 1945, respectively. The series is also called the Space Trilogy, though Lewis did not present it as a conventional continuous adventure series in every respect.

Out of the Silent Planet is set largely on Malacandra, Lewis’s fictional name for Mars. Perelandra takes Ransom to the planet Venus, while That Hideous Strength returns much of its action to Earth. The books change scale and style as the trilogy progresses.

The number is sometimes confused with the seven volumes of The Chronicles of Narnia. Narnia is a separate fantasy series. Lewis also wrote several other works of fiction, but only these three novels form the Ransom or Space Trilogy.