We were in the middle of a perfectly ordinary dinner when Father abruptly paused, turning from his half-finished squash casserole to steadily look at my younger brother and me and state: “I saw a changeling underneath your bed today.”

Mother frowned. “Stop it. You’ll scare them.”

“Don’t worry,” he continued, as if discussing the weather. “I’ll take care of it after supper.”

Once we had finished eating, Father went to the hall closet and dug around in the back for the bag that held his golf clubs. He selected a nine iron, firmly clenching it in his teeth.

He made sure to shut the door to our room behind him, leaving my brother and I outside, unsure whether we should cheer or help or go hide in the attic. There was a grunt, then a thump. Metal pinged off metal and I winced at the sound of glass breaking. More thumps sounded, spaced further and further apart until one final strike caused the door to rattle. Father’s muffled voice came: “And stay out!”

He opened the door, and set aside the now slightly bent club. “I broke your lamp,” he informed us. “Don’t go in until your mother can clean up the glass.”

Later that night, laying in bed with my brother curled up next to me, sleep eluded me.

Father had always been considered particularly eccentric, even for an artist. Nopony would say such to him directly, but I could not count the occasions in which, ignored by my elders, I overheard fragments of tactfully-phrased whispers that inevitably preceded an: “Oh, that explains so much.”

I also knew that many thought I had inherited his peculiarities in full. But he and I had a connection, and I knew that his quirks were never arbitrary delusions. He acted simply and with purpose, only in ways that the average pony could not grasp.

Perhaps his display had been a ruse, intended to reassure my brother, who often found himself plagued by nightmares.

But another theory troubled my mind. What if my father had indeed seen a changeling, and approached the matter with customary honesty? If that had been the case, it raised an unsettling question:

What if the changeling had won the fight?

I was unable to find solace in dreams. The next morning, I found Father sitting at the table, eating an orange. I went to the refrigerator, not looking at him as I scanned the shelves. I selected an apple that looked fresh.

We had plenty, and why not? It had always been Father’s customary breakfast.

From that moment onwards, I kept track of everything, carefully testing my suspicions. I checked our room, finding a splotch on the wooden floor, a stain of something imperceptibly darker. Was it still sticky? I could not determine if it was originally red or green.

When things ever-so-slightly changed over the next few weeks, I noticed. When Father took a break from his sculpture work, he trotted into the kitchen to surprise Mother with a kiss. In the afternoons, he acceded to my brother’s urgings to go and play in the yard where previously he might have complained of being too tired.

I noticed him watching me back, eyes slightly narrowed and brow creased in concern. I could disguise my suspicion, but I could not hide the way realization had choked out any love towards the creature in Father’s fur. He said nothing, only crept closer and closer to Mother and my brother, and more distant from me.

I couldn't risk checking out books from the library so I read in the aisles, picking through encyclopedias and bestiaries for information. I could not go to the authorities. I would resolve my problems on my own.

I chose Father's Day as the most fitting opportunity to act. Early in the morning, I rose, trotting past Mother in the kitchen and into Father’s studio. I nosed through his tools, selecting a thin chisel to carry back to his bedroom, where he lay twisted in the sheets, breathing steadily.

I had chosen his sharpest tool because I was uncertain if the chitinous exoskeleton would persist in disguise. As it turned out, the chisel sank deep into his chest with hardly any effort at all. His eyes flew open, some word choking out of his throat only to die on his lips.

I calmly waited, as the books all said that changelings revert to their natural form on expiration.

But of course, books could be wrong, too.