Most good stories start with a fundamental list of ingredients: the initial situation, conflict, complication, climax, suspense, denouement, and conclusion. Great writers sometimes shake up the recipe and add some spice.
Since I, Robot is a collection of short stories, we're going to try something a little different here. Here, we're going to break the plot of the whole book down—but we're going to do so as if this book were all about the robots as a single main character. We're calling this the "Rise of the Robots" plot.
Initial Situation
Stage Identification: "Robbie"
Explanation/Discussion: Here's the question that I, Robot asks: can robots and humans live together safely? Even though Robbie is really primitive (he can't even talk), Mrs. Weston is afraid of him. And even though Robbie is all kinds of awesome, robots still get banned from Earth (225). So some people clearly think that robots are dangerous to us humans. Are they?
Conflict
Stage Identification: "Runaround," "Reason"
Explanation/Discussion: Well, robots aren't dangerous but they can be a little unpredictable. Which is strange, because they have the Three Laws that they're supposed to follow. But these two stories show us that these laws have some wiggle room. This is part of the conflict in the book, because how can we be sure that robots are safe if these Three Laws have wiggle room?
Complication
Stage Identification: "Catch that Rabbit," "Liar!"
Explanation/Discussion: We could probably put these two stories under conflict. (Actually, "Catch that Rabbit" is a weird story that doesn't fit anywhere since the problem there has nothing to do with the Three Laws. Let's forget that story.) But if you think about it, "Liar!" really complicates the whole Three Laws by showing us a robot that wants to follow just one law—the First Law, the really big one—and he can't. This story also ends on a huge downer, with Susan Calvin purposely driving Herbie insane. So if the question of this book is "can robots and humans live together safely?," "Liar!" seems to say "no, because humans will put robots in impossible situations or destroy them." Oops—humans were the real monsters all along.
Climax
Stage Identification: "Little Lost Robot"
Explanation/Discussion: We think "Little Lost Robot" is a climax because this is the story that most seriously deals with the idea of robot rebellion. Calvin worries that the Nestors may be able to harm people. But at the end, even though Nestor-10 wants to attack Calvin, he can't. So, robots seem perfectly safe for people—even really weird robots like the Nestors.
Suspense
Stage Identification: "Escape!"
Explanation/Discussion: But if robots are safe for humans, what's going on in "Escape!"? The Brain seems to intentionally put humans in danger—and why? For a joke. Of course, it turns out that the Brain didn't put people in danger and everything is OK. (In fact, even though Calvin solves the mystery, it's not like anything bad would have happened if she didn't.) So we can all breathe a little easier.
Denouement
Stage Identification: "Evidence"
Explanation/Discussion: We know from the earlier stories that robots can get along with humans, but all those situations were under experimental conditions. Here we see the end-result of all these stories: the idea that a robot and a human can live side-by-side in the real world. If Mrs. Weston in "Robbie" was worried about robots replacing us, here we see that robot replacements might not be such a bad thing.
Conclusion
Stage Identification: "The Evitable Conflict"
Explanation/Discussion: And here's the kicker: can robots and humans live together safely? Yes—and, in fact, that might be the only possible way for humans to live safely after all. (Because, remember, we're very dangerous, both to robots and to each other.) Of course, this story raises questions about human freedom and destiny; so, in the end, we have a whole new set of questions.
So there you have it, in nine easy stories: robots start out as useful servants ("Robbie"); they become more complex and more problematic ("Runaround," "Liar!"); and they end up as indispensable partners—or masters ("Evidence," "The Evitable Conflict"). So, I, Robot has an arc (the rise of the robots) even though it's just a collection of stories. But although there's a definite arc to this book, it doesn't totally fit within the Classic Plot Analysis. Which is why you should definitely check out our Three-Act Plot Analysis and Booker's Seven Basic Plots Analysis, where we look at individual stories.