“Don’t you trust me?” Yejun said with a pout.
“Not at all.”
Something rustled inside the box, and I took another step back. “Is there somethingalivein there?”
“I sure hope so,” Yejun said, turning away and holding the box over the railing. “Otherwise, this was a waste of time.”
Before I could ask what he meant, he took off the lid.
A flurry of butterflies surged from the box and spun into the air, fluttering red and yellow and orange into the blue sky. They swirled around us, their delicate wings tickling across my face. I blinked quickly rather than swat them away—squishing a butterfly to death on my own eye was probably bad luck, not to mention gross.
A yellow butterfly landed on Yejun’s nose. He laughed and looked at it cross-eyed for a moment before gently blowing out a puff of air. It fluttered between us before joining the others in the sky. Yejun smiled as he watched them disappear.
He turned to me, then laughed. “Someone likes you,” he said.
I froze. “What?”
He reached forward, gently tucking a strand of hair behind my ear. I had half a mind to twist his wrist backward—and probably would have if not for the people around us—but when he pulled back, he had an orange butterfly on his finger.
“This one didn’t want to let you go,” he said.
“Oh,” I said, wanting to smack myself for not saying something halfway intelligent. Yejun always knew what to say, and here I was, fumbling through a simple conversation.
“Maybe your hair smells like nectar,” he said, turning to the railing and holding his hand out until the butterfly took off, chasing after the others. He waved as they dispersed. “Thanks for your hard work!” he said. Then he turned to me. “See? That wasn’t so scary, was it?”
I tucked my hair back, oddly conscious of how it smelled. “How will this change the timeline?” I said, rather than answer.
He squinted in the sunlight, stepping closer to me to avoid its rays. “What fun would it be if I told you that?” he said.
“Fun?” I said. “Is this supposed to be fun?” Betraying the descendants and plotting the downfall of Hong Gildong wasn’t exactly my favorite pastime.
He shrugged. “As descendants, there are so few surprises left for us,” he said. “Isn’t it nice to leave a little bit of mystery? Something to wonder about?”
I let out a sharp laugh, then realized he was serious. “I can wonder about what’s for lunch today, not whether or not the world is going to end.”
“How boring,” he said, picking up his Swiss-cheesed shoebox under one arm. “If you really must know, these thirty-four butterflies will pollinate a slightly higher number of golden asters on Jeju Island, where a Swedish billionaire will vacation in five months. His daughter will pick one of the flowers and tell her dad that yellow isher new favorite color, so he’ll start to buy her everything yellow that he can find. He’ll buy more shares in a candy company and get his daughter a private tour of the factory where they make butterscotch, and his investment will allow the company to distribute in Korea—at his suggestion—with a social media campaign that emphasizes the honey in candy corn, with lots of pictures of bees and flowers and, of course, golden asters.”
“Wow,” I said, blinking at the last of the butterflies on the horizon. “That’s…”
“Impressive, I know,” Yejun said, smirking. “I was training to be a timeline architect, so I’m good at scripting scenarios.”
Itwasimpressive, but I wasn’t about to tell that to Kim Yejun. “Did you get caught because you bragged too much about breaking the rules?”
Yejun scowled. “I got caught because I left a paper trail. Hence the milk.”
“I think milk can only do so much to protect us,” I said. “Now, are you going to help me with calculus, or are we gonna stand here until the timeline wipes us?”
“Right,” Yejun said, rolling his eyes. “Heaven forbid you help save the world out of the goodness of your heart. How could I forget the importance of calculus?”
Heat rushed up to my face, but Yejun had already turned away, waving for me to follow him like I was a dog. I stormed ahead, elbowing him out of my way just so he would have to walk behind me instead. When we took the elevator back down, if he noticed that my grip on his hand was tight enough to crush bones, he didn’t say a word.
Back on the lower level of Namsan Seoul Tower in the present day, Yejun slurped his bubble tea while shaking his head at my poor attempt at calculus. “That’s wrong,” he said through a sticky mouthful of boba.
My grip tightened on my pencil. I consciously relaxed every muscle in my hand—I was snapping too many pencils these days. “Why?” I said as patiently as I could manage.
“Because that answer defies the laws of physics,” Yejun said.
It had been forty-five minutes, and we’d only gotten halfway through the first page of my homework. I was starting to think that all this had been a mistake. I’d betrayed the descendants in exchange for an hour-long torture session.
