Which C.S. Lewis book is the first volume of his Space Trilogy?

Out of the Silent Planet is the first volume of C.S. Lewis’s Space Trilogy.

The novel was published in 1938 and introduces Elwin Ransom, a Cambridge philologist who is kidnapped and taken to Mars. Its sequels are Perelandra, published in 1943, and That Hideous Strength, published in 1945.

Lewis wrote the trilogy partly in response to scientific romances and space fiction that he felt often treated other planets as settings for human conquest. His books combine interplanetary adventure with questions about language, ethics, sin and redemption. The trilogy is also called the Ransom Trilogy because Ransom is its recurring central character.

The phrase Space Trilogy can cause confusion because the books were not published together as a single work. Out of the Silent Planet is the opening novel, while Perelandra and That Hideous Strength continue the sequence in that order.