Series · science fiction

The Space Trilogy

The Space Trilogy series by C. S. Lewis has 3 books and is best read in publication order, starting with Out of the Silent Planet (1938).

Books: 3 books
First published: 1938
Status: completed
Last checked: 16 August 2026

Start here: Out of the Silent Planet (1938) — then read straight through in publication order.

Book one

Out of the Silent Planet (1938)

Reading order

The order the books were released — the default way to read the series.

Book 1:
Out of the Silent Planet
Novel1938
Alternative text for cover: Cover of Out of the Silent Planet
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Book 2:
Perelandra
Novel1943
Alternative text for cover: Cover of Perelandra
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Book 3:
That Hideous Strength
Novel1945
Alternative text for cover: Cover of That Hideous Strength
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About The Space Trilogy

Before he became Narnia's creator, C. S. Lewis spent the years around the Second World War writing a very different kind of fantasy: three novels that take Christian theology into outer space. Out of the Silent Planet (1938) begins the trilogy by kidnapping Cambridge philologist Elwin Ransom and hauling him to Mars aboard a stolen spacecraft, where he discovers a world of three sentient species living in harmony under a guardian angelic intelligence -- and learns that Earth alone, among the planets, has fallen into corruption and been quarantined from the rest of the universe as the 'silent planet' of the title.

Perelandra (1943) sends Ransom to a young, unfallen Venus to stop a temptation from replaying the Genesis fall of humanity on a second world, in a novel that reads as much like a theological thriller as science fiction. That Hideous Strength (1945) closes the trilogy back on Earth, abandoning interplanetary travel for a much longer, satirical novel about a sinister scientific institute that has infiltrated an English university town -- pitting Ransom's small band of allies against a bureaucratic, dehumanizing conspiracy that Lewis modeled partly on his fears about totalitarianism and technocracy.

Written in the same years as The Screwtape Letters and his wartime BBC broadcasts, the trilogy works out the same Christian apologetics that shape Narnia, but for an adult readership and through the lens of golden-age science fiction rather than children's fantasy -- interplanetary romance, cosmic horror, and academic satire all serving the same underlying argument.

How to read this series

Read the trilogy in publication order -- Out of the Silent Planet, Perelandra, That Hideous Strength -- since Ransom's character and his knowledge of the wider cosmos build directly across all three books. Be prepared for a sharp tonal shift in the third volume: the first two are compact interplanetary adventures under 300 pages each, while That Hideous Strength is a much longer, slower satirical novel set entirely on Earth that reads more like literary fiction than science fiction, with Ransom appearing as a supporting rather than central character. Real background from Out of the Silent Planet and Perelandra is needed to follow That Hideous Strength's references to Ransom's earlier journeys, so this isn't a trilogy to sample out of order. No prior familiarity with Narnia is required, though readers who know Lewis's Christian apologetics will recognize many of the same ideas here in science-fiction dress.

Frequently asked questions

How many books are in C. S. Lewis's Space Trilogy?

Three: Out of the Silent Planet (1938), Perelandra (1943), and That Hideous Strength (1945).

What order should I read the Space Trilogy in?

Publication order. Ransom's knowledge and the trilogy's cosmology build cumulatively across all three books, and That Hideous Strength assumes you've already read the first two.

Is the Space Trilogy connected to Narnia?

No shared characters or setting -- it's a separate work written for adults, though it explores similar Christian themes to Narnia through science fiction rather than portal fantasy.

What is the Space Trilogy about?

A Cambridge academic named Elwin Ransom is abducted and taken to Mars, then later travels to Venus to prevent a second Fall of humanity, before a final novel set on Earth pits him against a sinister scientific institute.

Is That Hideous Strength really science fiction?

Loosely -- it's set on Earth with almost no space travel, and reads more like a satirical novel about a corrupt research institute than the interplanetary adventure of the first two books.