Tae-eul couldn't believe she hadn't thought of it before. If she and Gon existed in multiple universes, then why couldn't the flute? It was a matter of probability. Her hours of study had convinced her of that much. But if it existed, and this was somehow the same flute, how had she been able to find it? Why had she heard its music? It seemed like a major anomaly; like the way she'd been able to keep her memories after the portal closed. Had the universe finally decided to be kind to her? Or was she simply a loser who'd spent thousands of won on a useless old stick? She'd never been so excited to test a theory.

The sun had already set by the time she reached the bamboo forest and there was no one else around. She held the flute out in front of her as she walked, as though it were both a scientific tool and a talisman to ward off evil. She knew Gon would have laughed at the sight.

There had been times in Tae-eul's life when she'd felt completely certain of what would happen next, even though there'd been nothing concrete to explain why. This was one of those times. It was the feeling of stepping into a slipstream. A sense that events were aligning. The surrounding forest was quiet, but Tae-eul knew she was moving in exactly the right direction.

Her skin began to tingle. "I'm close now, Gon. I can feel it."

As though answering her thoughts, the air began to hum. She'd only used the flute once before, the time she'd dragged Lee Lim through the portal, but she knew what would happen next. The earth shook and the forest around her seemed to reshape itself as two enormous obelisks rose up from the ground.

Tae-eul stared, eyes wide in amazement, and then scanned the area around her, as if expecting Lee Gon to materialise at any moment. "Are you seeing this?" she would have asked him. "Did you know I could do this too?" She would have loved to see his expression just then. She shook her head. She was being silly. If Gon had known where to find her, he would have been there already. "I'll find him instead!"

Tae-eul bounded through the portal. The sight that greeted her on the other side was so radically different to what she'd previously encountered, she thought for a second she'd walked through the wrong door.

There was light. And air. There was soft sand under her feet. It almost looked like a beach. Tae-eul laughed in delight. "It worked! Gon really fixed it!" She broke into a run, kicking up sand and jumping with excitement.

Hair whipped around her face as she ran. She hadn't felt this happy in months. She reached another gateway and leapt through, daydreaming that in a matter of seconds she'd come face to face with the King.

Her hopes were immediately crushed. The world on the other side of this door couldn't have been more different to Gon's world. There wasn't even a forest. It looked like a city that had been hit by an apocalyptic war. Gray ash and rubble stretched out as far as the eye could see. She gasped and scrambled back through the gateway, clutching the flute to her chest.

She lay on the soft sand, staring up at the sky and breathing deeply as she tried to order her thoughts. "Gon put back everything back in its place, but now that means there's more than one door. So how do I find his world?" A thought hit her and she sat bolt upright. "How do I get back to mine?" She jumped up in panic and retraced her footprints.

She eventually found the gateway she'd come through. She took off her coat and laid it in at the entrance. "Ok, can't lose track of that one," she thought with relief. She looked around again. The sand seemed to stretch endlessly to the horizon. "How far does it go? How many doors can there be?" She started counting as she walked.

When she got to 200 she stopped. She'd already trekked quite far. Her brown coat was now a spec in the distance. Her heart sank. She wondered if in this repaired version of the In-Between the doors to their worlds were on opposite ends of the map. "Is this why you never found me, Gon?" She began the long walk back to her gateway in low spirits.

She had almost reached her coat when a patch of white caught her eye. The sandy path was wide, and she hadn't noticed it before. She wandered over. She almost couldn't believe what she was seeing.

There, sticking up through the sand as though it were a completely normal place to grow, was a host of white flowers. Magic lilies. Tears pricked Tae-eul's eyes. Seeing the lilies growing there so well, despite the strangeness of their surroundings, gave her a small feeling of hope. It was like finding a signpost in Wonderland.

A thought struck Tae-eul. What if they were a sign? What if they were evidence that she was getting close? She looked up past the flowers, and realised there was a door a few meters away. It only took a moment to put it all together.

She'd planted lilies in the broken In-Between. What if these were the same flowers? What if they were growing in this exact spot because this was where Gon's gateway had always been? Maybe Gon was using them as an anchor point, to find his way home each time… She felt excitement welling up again. She took a few steps towards the gateway, and was about to cross through, when a voice at the back of her head told her to stop. "Wait. Think for a moment." She patted her pockets, looked down at her clothes, and realised she was completely unprepared.

"I don't have any of their money," she thought with frustration, "and my phone won't work there. Plus it might be nighttime... I'd have to find a hotel." Then she thought about her dad, and how he'd worry if she vanished without a warning. "Ok, new plan."

The next two hours of Tae-eul's life were mostly a blur. She'd raced back to her dimension and jumped straight into a taxi, asking the driver to take her to the nearest jewellery shop. It was getting late, but some stores were still open. She then maxed out a credit card buying gold, and jumped into another taxi to take her home. On the way she'd emailed off a leave request to the station, asking for all 21 of her vacation days at once. It was automatically approved.

Her dad looked surprised as she barrelled through the front door. "I'm going away for a while!" she announced to him on the way to her bedroom. "It's going to be a big trip!" She began stuffing clothes into a backpack, hiding the pieces of gold in a side pocket. At first she didn't pay much attention to the items she put in. Then she saw a dress at the back of her wardrobe, and debated whether she should pack something nice. A fews seconds later she shook her head and laughed. She'd never worn clothes like that around Gon. He probably wouldn't recognise her if she started now.

Her training as a police officer prompted her to pack a few items she might have otherwise left behind, like a pocket knife, flashlight and a map of Busan. She also threw in some protein bars and bottled water. "Who knows what I'll find!" she thought to herself.

When she was little her dad had nicknamed her 'the Unstoppable Force', because she always made things happen once she set her mind to something. Now as she pulled on her backpack and entered the living room to say goodbye, she could see her father wasn't shocked at the sudden departure. "Appa," she began, "there are some places I want to explore. I might be gone for a long time, but I'll be back. I promise."

He smiled at her and nodded. "Ok, ttal. Take care. Bring me back some souvenirs."

"Of course!" She was about to leave, but remembered something at the door. "Oh! And if someone comes looking for me while I'm gone, appa, tell them I've gone down the rabbit hole."

Half an hour later she was back in the In-Between, standing next to the patch of magic lilies.

Her excitement was bundled up with nerves. There were so many things that could go wrong, but for once she was willing to take a leap of faith. She'd brave the unknown to find Gon. She'd cross the whole universe, if that was what it took.

With a deep breath she stepped forward, through the gateway and into the world beyond.