Doc Homer is looking for the girls during a flood. They're only little, so we must be in a flashback or something. Dude's trying to find the girls in the rain, in the dark, with a flashlight.
Doc's still grieving over the death of his wife, and he's constantly scared that his girls will die, too. He thinks about how easy it is for little kids to die in the desert—they could just eat an oleander leaf and turn blue like that other kid.
Whoops. It's just a dream.
As it turns out, Homer's in bed, it's the present day again, and he remembers that on the night when that flood happened, he wasn't even in Grace. Someone else saved his seven-year-old daughters: the husband of a friend named Uda Dell.
The girls had been hiding from the flash flood in a coyote burrow. They were hunkered down with a bunch of coyote pups, and they couldn't take the pups with them when they were rescued. Doc remembers them crying as if they were drowning pups themselves.
Doc asks himself "why does a mortal man have children? It is senseless to love anything this much" (3.9)—proving that though he appears to have the emotional depth of a contact lens, he's totally just faking it to protect himself from grief.