You know how earlier the narrator said that Cathy was a monster? Well, now he's wondering, since we can't really know what Cathy's motivations were or why she did the things she did.
Cathy gets bigger and bigger with pregnancy, but only in her stomach. The rest of her doesn't change. She also develops a weird craving for lime.
The Hamilton men begin their work on the wells, and as summer turns to autumn, Adam's life is just as dandy as can be, with everything going his way.
While the Hamilton men are drilling, they hit something that mangles the steel. Samuel's eyes light up when he comes to the conclusion that it must be a meteorite that hit when the valley was still an inland sea.
As the three of them are talking, Lee comes galloping up to them. Cathy has gone into labor and Samuel said that he would stand by, given his excellent track record with babies.
Then Samuel asks how things are with Cathy. Lee doesn't say much, and just insists that Samuel see it for himself—he finally lets it slip that it seems more like a battle than a birth.
In Cathy's bedroom, all of the windows have been covered with blankets. When Samuel takes them down, Adam gets all protective of Cathy, but Samuel basically tells him to stay out of his way and go wait outside.
When Samuel has a look at Cathy, he sees murderous hatred in her eyes. At first Cathy doesn't say anything to his questions, but as he gets shorter with her she puts on her act.
Samuel fastens Liza's pulling rope to the foot posts of the bed. Cathy has a contraction, but instead of screaming she just emits a few grunting squeals.
As Cathy thrashes Samuel puts his hand gently on her forehead, where her scar is. She bites his hand and mangles it; afterwards she attributes this to the pain.
The birth happens really quickly, and Samuel barely has time to give the baby to Lee (it's a boy) before he realizes that Cathy is actually having twins.
The second one is also over quickly. Cathy doesn't even use Liza's pulling rope.
Cathy's face is void of emotion. She tells Samuel that she doesn't want to see the boys, that she doesn't want them.
Samuel tells Cathy point-blank that he doesn't like her (you go, Samuel), but she just tells him to cover the windows and send Adam in.
Adam doesn't seem very interested in his two sons. He goes into the room and Samuel can hear him nailing the blankets back up.
In the kitchen, Samuel and Lee talk about what just happened while Lee attends to Samuel's hand. Samuel says that maybe all of his feelings of foreboding were right all along.
Samuel knows how to test to see if he and Lee are just over-thinking it, and he sends Lee to go get Liza.
Samuel goes to the bedroom and hears Cathy telling Adam to leave, but he insists on staying with her.
Liza arrives early the next morning and sends Samuel to the doctor in King City for his hand. He burns with a fever for three days while Tom feeds him chicken soup.
Liza stays at the Trask place a week and takes control of everything. She sees that Cathy won't be able to nurse the children.
When Liza comes home, Samuel asks her about the babies and the Trasks. She doesn't like Cathy though she doesn't know why, and she can see that Adam is head over heels for her.
Samuel says that if the two of them are incompetent, then who is going to take care of the infants?
At which point Liza brings up Lee. She proudly announces to Samuel that Lee is Presbyterian, and he is the one taking care of the boys.
It takes Cathy a week to gather her strength. One morning Adam tries her door and finds it locked. He can hear her opening and closing drawers inside and assumes that she is putting her bureau in order.
Lee comes to Adam that afternoon and says that Cathy told him to go into King City to buy bottles. She also told him to take the weekend off and not come back until Monday. Lee tries to find a reason to stay but Adam sends him away.
When Adam knocks on Cathy's door for supper she is standing in her travelling dress. She tells him that she is going away.
He doesn't believe what he's hearing, even though she had told him before. He's all what about the babies, and she tells him to throw them in a well.
Adam shoves her back and locks her in her room in a panic. He hears her open and close a drawer and his immediate thought is that she is going to stay; from the other side of the door she sweet-talks him and apologizes.
When Adam opens the door Cathy is pointing a gun at him. She shoots him in the shoulder, tosses the pistol on the floor, and walks out of the house. Adam can hear the twins crying because he forgot to feed them.