The chimeras need feed. Their trough is empty except for pieces of orange rind strewn like busted taillights. They spit cud at its sides in protest. Their trough is an old fishing boat, Eddie’s dead father’s; the mushy lumps thud hollowly against the metal, inching the boat across the dewy grass at angles.

Eddie goes to the barn to prepare their feed. A lump, greenish, clips his arm from behind on the way. Per Dr. Wu’s instructions, and the American Heart Association’s recommendations, each serving of feed includes a measured blend of fruit (primarily citrus), legumes (beans, peas), vegetables (broccoli, zucchini), and whole grains (such as oats), tossed with cod liver oil. The chimeras also graze the field around Eddie’s mother’s house, munching grass and preferring weeds, as all other sheep. The feed Eddie makes is supplemental, for the chimeras’ hearts, which are human.

In the barn is hidden a U-Haul that dominates the space and instills it with a warm metallic odor. Flabby sacks of oats slump under a long workbench. On top of the workbench, a commercial-size container of peanuts is overturned before stacks of the feed’s other ingredients. Peanuts sprinkle the dirt floor. Once again Eddie surveys the barn to see how the chimeras might have gained entry. There are only the doors, which are kept latched, and a row of new freezers blocks the back one. This is not the first incident. It appears the chimeras are breaking into the barn, though Eddie suspects his mother Jan is responsible. Soon after he and the chimeras arrived two weeks ago, he caught Jan concocting them a snack, using incorrect proportions. Jan believes the chimeras get hungry in between feedings. In addition Jan thinks the chimeras may be humans trapped in sheeps’ bodies. This is why she feels sorry for them, this was why she was making them a snack in the first place. Just when Eddie has her convinced that they’re sheep trapped in sheeps’ bodies—except for their hearts—she circles back to the one with the thumb on its forehead.

The thumb, not the hearts, is Jan’s real hang-up.

The thumb is the government’s hang-up, too.

Under Dr. Wu, Eddie works as a research assistant in a University of Nebraska lab that, for years, has developed human hearts in sheep so that one day livestock may act as organ donors. For a heart to grow, a subpopulation of adult human stem cells must be injected in the brain of a sheep fetus during a window halfway through gestation: before the fetus’s immune system learns to detect foreign cells, so it can’t reject them, but after the blueprint for its body forms, so it looks normal. The timing and site of each injection are the variables. These are being perfected. The current chimeras’ hearts are between eighty-nine and ninety-two percent human.

Also there is the one with the thumb, whose heart is more like ninety-seven.

As soon as its head jutted out from its mother, thumb-first, Dr. Wu saw he had injected it too soon. Still the lab managed to hide it, studying it in secret for fifteen months. Then, three weeks ago, Dr. Wu got wind that the University was launching an investigation. Bioethics committees from the Department of Agriculture and the National Academy of Sciences would assist. Both had endorsed the cultivation of internal organs when Dr. Wu proposed the project, but anything visibly human they had advised against. Limbs and dicks, as one ethicist said, were yuck factors.

Dr. Wu decided Eddie should take the chimeras on vacation. He said he would send Eddie a text message when they could return, when he was assured of the project’s future.

But that was three weeks and three states and five dead chimeras ago.

Now Eddie feels like a shepherd with a master’s degree.

Eddie fills the wheelbarrow with its first heap of freshly mixed feed. He glides the load toward the door. In the corner next to the door lie three stray oranges. One of the oranges, as if stirred by observation, rolls several inches toward the wheel then rests again.

Outside, Eddie contemplates checking the chimeras’ breath for a nut or citrus odor. The chimeras gather around the wheelbarrow before Eddie makes it to the boat, gorging and butting. Predominantly the chimeras are Katahdin sheep, a hornless breed with hair instead of wool, selected by Dr. Wu for these reasons. This way the chimeras don’t need shearing, and the scientists don’t need gear to guard against ramming. Also Katahdin sheep possess a natural resistance to internal parasites.

Sometimes Eddie thinks of things like love and devotion as internal parasites.

Abruptly he notices that one of the nine chimeras, the one with a thumb like a horn, is unaccounted for.

Then Jan comes into view walking toward the field, inching bigger and bigger as she closes the distance. The missing chimera grows behind her. Jan is one strange-ass specimen. These are the words she uses to describe herself after she mistakenly dials her own phone number, accidentally throws away cash, or searches for her keys only to find them having been in her hand the whole time. Eddie doesn’t consider his mother that strange, though her hair is longer that that of any female he has seen past puberty. Jan is sixty-two. She wears a voluminous shirt that belonged to one of her three dead husbands; the shirt, unbuttoned, cocoons a white tank top and black leggings. Her body has been whittled thin by a bellydancing class geared toward widows.

Recently, however, Jan has skipped several bellydancing classes to tend to a new hobby: aiding and abetting fugitive animals.

“This one”—she points to the chimera following her—“this one came to the door crying. Crying, Eddie. It knocked.”

The chimera sniffs Jan’s waist. Sure enough the hair under its eyes is matted against its skull, wet. Though pools could just as easily have gathered there from the sweat running from beneath its hood. Jan sewed the hood, which covers it thumb, to render it less conspicuous—and less self-conscious—among the flock.

“It didn’t knock,” he says. “It butted.”

“No, it was gentler than that. More like—it was tapping, Eddie. It must be starving.”

“Tell me the truth,” he snaps, “are you feeding them yourself?”

She looks incredulous. “You told me not to!”

“I’ve been finding things left out,” he tells her for the first time. “Things spilled. Like someone forgot to clean up her mess.”

“It’s not like a sheep to go wandering off by itself. It’s like a human.” She reaches down to rub the chimera’s ears, which protrude through perfect-size holes in the hood. She eyes the barn. “They could lift those latches on those doors with their noses. They get out of that sorry-ass pen the same way.”

He keeps studying her face. “One time, one of the freezers was left open.”

Jan gazes at the field enveloping her house, the subtle hills rippling north. Farther away, a small forest swells west. Her searching eyes are almost hopeful, almost as though they expect something miraculous to emerge any second. “I wasn’t looking at what’s in those freezers.”

Eddie considers the pen he and his mother rigged together. “Maybe we should keep the chimeras in the garage.” Though he thinks the garage is too small. He remembers the U-Haul, in which they traveled. The other five that didn’t survive the trip.

The one with the thumb nibbles the ends of Jan’s hair just above her butt.