Ylla and Yll K are a typical 1940s suburban couple, except for the teeny little fact that they're Martians with "yellow coin eyes" (3). Yll goes into the city to work while Ylla spends her days cleaning the house with magnetic dust. You know, just like Grandma used to do.
These two crazy kids used to be happy together. As Bradbury tells us, "Once they had liked painting pictures with chemical fire, swimming in the canals in the seasons when the wine trees filled them with green liquors, and talking into the dawn together by the blue phosphorus portraits in the speaking room" ("Ylla," 3).
Ah, young love. But now, as Ylla thinks, "Marriage made people old and familiar, while still young" ("Ylla"). In other words, Yll would rather read a book than talk to (or touch) his wife.
So it's no surprise that Ylla ends up being dissatisfied with her life and wanting more. Here's our favorite line from her, which sounds like something any unhappy woman might say: "I'm sad and I don't know why, I cry and I don't know why, but I'm crying" (217). (Maybe she can find someone to prescribe her mother's little helper?)
Yll is something of a villain in this piece; it's hard to sympathize with him when he doesn't sympathize with his wife. In fact, when Ylla tells him about her dreams, Yll tells her "If you worked harder you wouldn't have these silly dreams" ("Ylla"). (Question: worked at what? Cleaning house? We suspect that's not going to make anyone feel more fulfilled.)
Ylla is something of a protagonist, since she's the one who feels things deeply and has hopes for the future—hopes which, unfortunately, don't materialize.
Okay, well, actually they do materialize in the form of the two Earth Men who land on Mars. But Yll shoots them. Do you get it? Yll is literally killing Ylla's hopes and dreams. Hey, no one ever said Bradbury was subtle.
Here's the thing: Yll and Ylla K show us that things aren't all that different there from back on Earth, so it makes sense that their story comes first, or at least first after the "Rocket Summer" interchapter. Their story lets us know that, even if Bradbury is writing about Martians, he's also writing about us.
Oh, yeah: except that the Martians are telepathic, which becomes important in the next stories.