Of Other Worlds is split into two parts. The first consists of essays on literature, while the second contains short stories (and five chapters from an unfinished novel) that Lewis wrote. I will summarize each separately, but they are all so short that if you want a refresher on what they are about, it's probably better to just reread them.

"On Stories". In the first essay, Lewis argues that the Story, as an independent element in a novel, is not given enough attention. He also attempts to deal with the criticism that romances are worthless. Here he argues that if people were simply seeking adventure or excitement in these novels, then you could replace any one danger with another, and the effect would be the same. For example, if someone is being attacked by pirates, you could make them being attacked by regular robbers to the same end. (He gives several other similar examples.) Obviously, this isn't the case, as the image of pirates carries with it so much more.

Ultimately, Lewis admits that romances may not be the greatest works of literature, but if you are going to write a romance, you may as well aim for a great one, that captures all these intangible elements of Story that are so critical to the reader's enjoyment. Another point that Lewis makes repeatedly is that if something is worth reading more than once, than obviously people were not just seeking the excitement aspect of the book, because all the surprises have already been ruined. Something else must be driving them on, which Lewis argues is Story.

"On Three Ways of Writing for Children." In this essay Lewis presents three ways of writing for children - one which is bad, one which is good but he does not do, and finally the way he writes for children. The bad way is to fabricate things that you think "modern children" want in their stories, as though they are somehow different from other readers or children in other times.

The second way is a story that grows out of telling a story to a particular child. This is different from the first in that it is the result of an actual, real relationship between the author and the child. There is no fabrication of what some non-existant modern child may want, but a development of what a particular child is interested in. He gives Tolkien and Lewis Carroll as examples of authors who do this.

The third, and the way Lewis himself writes, is that you have an idea (or a picture in Lewis's case) of a story that needs to be told, and a children's story simple happens to be the best vehicle in which to tell that story. Thus, the audience could be adults or children, but the style is children's because that's what the story requires. As Lewis says multiple times, if a story isn't worth reading as an adult, it was never worth reading to begin with. "I am almost inclined to set up as canon that a children's story which is enjoyed only by children is a bad children's story" (24).

Lewis then responds to the criticism that it is improper, or embarrassing for adults to enjoy children's stories. He gives three points. First, it is more childish to be concerned with what others will think about you than it is to read children's stories. "When I became a man I put away childish things, including the fear of childishness and the desire to be very grown up" (25).

Second, he argues that growth is not replacing what you take pleasure in (that is, replacing children's stories with "adult' stories) but in adding to what you find pleasure in. He uses food as an example. Honey is not childish just because children like it.

Third, associating fairy tales with children is a recent occurrence. It is only because fairy stories went out of favor that they became relegated to children (the same thing happened with furniture according to Tolkien). Historically, fairy stories have been for everyone, not just children. He also goes on to point out that fantastic children's stories often give a more realistic view on life than "realistic" stories that present a false view of the real world, as he believes books about school for children often do.

"Sometimes Fairy Stories May Say Best What's to be Said". This short essay discusses the ways in which fair stories are at times the best method by which to write a story. This should be determined by the story, though, and not decided on beforehand. One way in which fairy stories are superior is that they do not require the deep characterization that other works of literature do.

"On Juvenile Tastes". This essay reiterates much of what has been said before. "The right sort work from the common, universally human, ground they share with the children, and indeed with countless adults. They label their books "For Children' because children are the only market now recognized for the books they, anyway, want to write" (41).

"It all began with a picture"¦" For Lewis, his stories have all begun with pictures which, when strung together, become the story.

"On Criticism". In this essay, Lewis discusses the things an author can learn as a critic, by reading others criticisms about his own work. The idea, Lewis points out, is that there are some things an author knows best about his book, and thus the mistakes critics make in regards to these items are blatantly obvious. Thus, the author's own ability to critique the works of others can be improved by keeping these things in mind.

Lewis first briefly touches on the need for critics to be honest. He quickly moves on to his main points, the first of which is the need for a careful reading of what one is critiquing. In particular, critics must be very careful about saying something or other never happened. Obviously, an author knows best if they did or did not actually do what a critic is saying.

Next, critics assume they know facts about the writing of a book that they don't, such as when they were written, the order in which they were written, the inspiration or psychological motives for writing, and the conditions under which a passage was written (i.e. this part was inspired). In this last regard, it is most likely the critic is trying to say something else (such as it sounds inspired because of certain elements) in which case they should say that instead.

He also spends some time pointing out that one should never offer a criticism of a style of writing that they knowingly hate, or have a previous prejudice against. Nor should they review something in which they have a relationship with the author (such as if that author recently said something bad about their own book).

In "On Science Fiction" Lewis discusses the sub species of science fiction. One bad type is when an author sticks a normal story (i.e. a love story) in the distant future for no apparent reason. The futuristic setting should only be used if it adds something to the story. He gives other sub species (such as the engineering type) as well. He concludes by pointing out the powerful reaction people have towards science fiction (some go to it compulsively, others flee from it in terror).

"A Reply to Professor Haldane" gives Lewis an opportunity to exemplify many of the items he points out in his discussion in "On Criticism". Haldane's criticism was about That Hideous Strength.

"Unreal Estates" is a conversation between Lewis and several friends about science fiction.

"The Shoddy Lands". The main character meets with a friend and his fiancé. Suddenly, the narrator enters a world where everything is shoddy and out of focus. He walks along, finally seeing roses, and daffodils in focus. Next, shops become clear, but they are all women's shops. There are people surrounding him, but only some faces or clothes are in focus.

Finally, he sees a giant naked woman, who he realizes is his friend's fiancé. He suddenly returns to the real world, where he offers conjecture that he was seeing the world as Peggy (the fiancé) must see it, with only those things she cares about in focus. He ends with the hope that no one ever enters his own mind like that.

"Ministering Angels" - A group of scientists, and a meteorologist who is seeking spiritual enlightenment, are nearing the end of their three year term on Mars. A ship arrives unexpectedly with two females on board - a psychologist and an elderly prostitute. They explain they have come to serve the sexual needs - "Woman's Higher Aphrodisio-Therapeutic Humane Organisation (WHAT-HO)" - of the men on Mars. Evidently they never considered that the men would not be interested in sex with these woman.

One of the men stationed on Mars joins the crew of the other ship, and they mutiny, leaving the second captain and the women on Mars. The religious meteorologist realizes he may be on Mars for the spiritual edification of these women, rather than just himself.

"Forms of Things Unknown" - a young man decides to go to the Moon, in spite of knowing that the last three expeditions resulted in the crew arriving, saying they were okay, but then remaining silent before they can finish their initial messages. He arrives safely, and finds statues of the men. However, when he turns and sees his shadow, he is frozen in place by the image of his ex-girlfriend.

"After Ten Years" - five chapters of an unfinished book that was meant to tell the story of Menelaus after his victory in the Trojan War and rescuing Helen. It was going to deal with Helen, aged, and potentially the idea that Menelaus must choose between the real, aged Helen and a beautiful Eidolon (a fake fashioned by the gods) at some point. This conjecture comes from a friend of Lewis after the five chapters