Two, one two three four.
Have not yet read Then We Came to the End but intend to, at some point, but from what I've read of it this is in some way similar, finding surreal moments of existential crisis in banal, universal social reality.
Because I'm pleased with myself for spotting a stylistic device of his, I'm going to point out the ways in which Ferris unseats his character's relation to reality. It's mostly a matter of filling story-space with disruptions in perception:
He ended up by the gas fireplace below the mantel and mirror.... He stared at it until his eyes began to hurt, letting the competing voices behind him blend into one festive gibbering blur. When he looked up again, his eyes had hung a scrim of fire between him and the world. He could see only the vaguest shapes, the crudest outlines of people and walls, and then only at his periphery. He waited for the image to dissolve, but before it did completely a familiar voice said, "Well, look who it is."
He heard her rummaging through the closet. When she came back in, she switched on the overhead light just as he happened to be staring at it. His eyes burned and he turned away. The next thing he knew, she had placed a roller bag on the bed and was unzipping it.
On his way back in, he said, "O.K., I've got it."
He found the room empty. Her wedding ring and the one with the diamond were on the counter, where she always put them before starting to cook anything. The sink had filled with dishes. On the stove, a big pot and a smaller one with a handle unfurled steam into the beige hood where the vent rattled. The door of the cabinet under the sink hung open. He checked the bathroom off the kitchen. He returned the way he'd come, through the apartment, in the unlikely event she had passed by without his noticing as he was sitting on the sofa. He returned to the kitchen, to the animated appliances and stewing ingredients. She came in through the front door.
"Where'd you go?"
"Took the garbage down," she said.
He walked through the front door and called out to her. He went through the apartment to the bedroom. The bed was unmade in that corner where she had lain flipping through her magazine, and the magazine itself was on the duvet. He looked in the bathroom before leaving the bedroom and walking back through the apartment, this time turning on all the overhead lights. On his way to the kitchen, he stopped at the closet and took an accounting of the coats, then he hurried on to the kitchen, where everything was as it had been a few hours earlier... Her wedding ring and the one with the diamond remained on the counter, where she had left them before she started cooking.And all this is what makes the story more than a merely ("merely"?) unnervingly accurate portrait of relationship, a guy who's so self-satisfied that he doesn't know when to stop ragging on his wife's "predictable" friends, and then has his sense of his relation to the world reversed. Ferris dramatizes this upending not just through his spot-on narrative and details, but by denying his protagonist a stable place in the world.
When he returned to the bedroom he found her on the far side of the bed with her back to him.