Katie should've been asleep. I wasn't either, but that's beside the point.

The bigger problem was that only rumpled covers lay on her bed, the single sign of Katie's presence.

She's probably just in the bathroom, or getting some water. I rolled over, but a nervous energy spun in my gut, keeping sleep just out of reach. A battle raged inside me for what felt like a century — though in reality, it was probably just a few minutes — before I climbed out of bed. I already knew that Katie hadn't returned to her bed; if she had, I would've heard the door creak open, the soft rush of air in and out of her lungs. I pulled on leggings, a sweater, and a pair of tall boots, the first things I grabbed out of my closet, and headed for the front door.

For a moment, I considered waking Mom and Dad. But the thought quickly dissipated. I couldn't rat out my twin, even if she was breaking the one rule we've been given.

It all started when we were five. Every year, at the end of October, Katie got the same glassy look in her eyes. She tossed and turned in her bed, sometimes woke up screaming, all from a voice that she claimed was playing in her head. The first eight years, I never took it too seriously, none of us did.

That is, until the day of the rescue. Mom coined the term to refer to that fateful night when we found Katie floating in our pool upside down, her head submerged. Mom couldn't bring herself to talk about what actually happened that night — the supposed voice in her head called her to the water. Instead, she prefers to remind us that Katie was saved, perhaps a more positive outlook on the event. Perhaps it's also a guiltful reminder of the burden she caused, a debt she now owes.

Now, this time of year, neither of us are allowed outside of the house after dark. Katie and I both agreed that the rule was good and tried to abide by it. Our only obstacle is the voice in Katie's head.

There were many precautions placed to make sure Katie doesn't get out. Unfortunately, they all seemed to have failed tonight. The moment I left my room, I spotted my twin's escape route, a smashed window on the second floor of our house. Mom and Dad must've been pretty sound asleep downstairs to not have heard it. Come to think of it, I must've been, too. Unless the noise woke me and I didn't realize it...

I didn't have time to puzzle this out. A tree branch extended toward the smashed window, and I grabbed hold of it. The rough bark bit into my palms as I climbed down, careful to not lose my footing. The chilly air swept away the last of my drowsiness, and I ran around the back of the house the moment I reached the ground.

Katie wasn't there. Ordinarily, I would've breathed with relief. Not tonight. Fresh terror simmered in my chest, and I desperately scanned the yard for any sign of my twin, a single footprint, a scrap of fabric.

And then I heard it. My ears caught a flicker of a melody. It was barely enough to go off of, but still, I whirled in the direction I perceived it to come from and tore down the street. It morphed into a tinny dissonance, singular at first, but growing louder and louder the longer I ran until a thousand off-key mice screeched in unison. I focused not on the pain splitting my head, but on the fact that I was going in the right direction.

Before I knew it, the cacophony brought me to a forest. Dark silhouettes hovered over me as I ran into it, claw-like branches outstretched and ready to capture me at any moment. My heart was beating so fast that it broke the tendrils of fear encircling it. I forced myself to keep going forward, to follow the noise to Katie.

In the distance, a pale figure glowed among the trees. I hurried my pace.

"Katie!" I screamed.

A laugh rang through the forest, deep and round, like bass notes on a piano.

"Catheryn." Its whisper snaked around me, vibrating through my core. I pushed onward.

"Katie!" I screamed again. I could see her better now. She stood atop a ridge of rocks and moistened, murkey clay, overlooking a body of ashen water.

"Two little girls for the price of one," the voice hummed again. "As they say with double yolks, I must've been lucky this time."

My head pounded, and my lungs screamed louder than the falsetto in my ears. I had to get closer, to reach her before it was too late. But a force encased my limbs, an anchor rooting me to the earth. I fought with every last bit of strength, but I only moved an inch.

"Katie!" Tears soaked my cheeks. "Kate—" No more sound would escape my lips.

"You'll destroy your throat," the voice sang. "Not that it matters anyway."

I put all my energy into focusing on my sister. Please! Don't do this! Turn around!

By some miracle, she did. At first, Katie's eyes were glazed over. But after a few blinks, the haze melted away.

"Ryn," she gasped. Then more loudly, "Ryn!"

I sobbed uncontrollably now. I mouthed, "don't jump into the lake!"

She stumbled backward from it like she'd been stung. She started toward me, but she froze. Her course reversed, a force dragging her back to the water. An inch of space opened in my throat, and I burst out,

"No!"

Instantly, my throat constricted again. Yet Katie managed to fight the force back a few inches.

It can't handle both of us.

I thrashed at the force, and, as if she'd read my mind, Katie did the same. The weight on my limbs lessened. Our strategy was working.

A sigh rippled through the trees.

"Must I fetch the girls myself?"

The water began to stir and bubble. Rubbery skin emerged from below the surface. Two yellow eyes blazed through the night, burned into my skin. Its monstrous jaw hinged open. Though rotted, its six rows of teeth still formed razor-sharp points.

As it drew closer to the water's edge, so did we. In the process, the grip on my voice loosened.

"Don't let it take you!" I yelled.

"I don't want to," Katie whimpered back. Again, the force clamped on my throat, but I fought harder. The force was weaker than us both.

"Katie, scream!" I choked out.

I channeled all my energy into my vocal chords. It didn't matter that no sound came out. I could feel the power loosening around me. Step by step, I worked my way back from the water. After several minutes, I realized that the monster wasn't pursuing us. It must have been tied to the water.

We thrashed past tree after tree, until finally, finally, the force released its hold, and I dropped to the ground. I gasped for breath, my throat raw. Stillness settled over the forest, no more screeches or songs. We must've scrambled outside the voice's dominion.

An inkling of the voice swept by. "You put up quite the fuss, little girls. Be grateful that your luck tired me out. But be sure, I will see you again next year."

All went silent. I was barely aware of my surroundings. My heart and lungs still beat in an elevated rhythm. The only other thing I felt were the fingers interlacing with mine.

Katie. She was safe.