There wasn't much Link could do after discovering what Midna meant by the orb of the Twilight realm. He returned to Hyrule and told everyone what he had discovered, and he, Shad, Ashei, and Zelda spent hours looking through the few books and scrolls about the Twili realm, but nothing about the orb, where to find it, or how to go between the realms without the portal was written. So, with few options left, Link went to the Mirror and waited. He debated if he should go to the mirror or to the spot where Midna had first appeared to him, but in the end figured that the Mirror must still have some magic left, so it would be easier for Midna to use it up and get to him.
He'd been camping there for a few days, discussing the orb among other things with the sages who appeared every now and then, when at long last a flicker of light appeared by where the mirror once stood. Link, who had been playing a card game by himself, caught it in his peripheral vision. Turning, he suddenly saw a burst of light much brighter than the original flicker, like a bomb exploding. Link lifted up an arm to shield his eyes, and when the light faded and he could lower his hand, there was Midna.
She was crouched slightly, like she'd just landed after jumping. She straightened up to her full height, the hood to the robe she was wearing falling away from her flaming red hair. She turned her red eyes, surveying the area, before they met with Link's blue ones. She smiled, while Link gaped openmouthed at her, and said "Hello Link." She tilted her head sideways, looking at him with an amused expression. "What? What is it?" Then, she grinned wider and said "Am I so beautiful that you have no words left?" And the tension was broken. Link ran towards her and grabbed her into a fierce hug. He buried his nose into her shoulder, squeezing her tightly. Midna hugged him back with just as much force, her arms looped around his neck. Link pulled back and looked at her, his eyes saying all.
Midna sighed, and closed her eyes. "I'm sorry Link, I'm so sorry." And then she pulled him close again, a stray tear leaking out. "It…it was better that our worlds weren't able to mix together again…it was too risky..." She mumbled into his shoulder. Link sighed like he'd been holding in a breath, like he'd been holding it in since she left and he was finally relieved.
He looked at her again, smiling, and his eyes seemed to say "It's okay." Midna smiled back, and broke away from him. Her eyes turned serious. "Link, we have work to do. Will you help me find the orb of the Twili realm? It is most certainly here, in Hyrule. If it were in the Twili realm we would know. The land would not be dying like it is…" Midna said quietly. Link put his hand on her shoulder, and nodded firmly, showing that he would help her. She let out a breath of relief. "Good, because it is your world in danger too." She said. "My people are not thriving and they struggle to survive. Now that one of the two orbs that provide for us is missing and most definitely not in our realm, there is talk that someone from the world of light has stolen it. If it is not returned soon, then there is talk of finding a way to break through to this world. After all, if someone from the light realm was able to do it without the mirror, then certainly the shadow dwellers are. Once they get here, then they plan to overtake it with Twilight again, while also searching for the orb. Even if it's found they won't give the light back. We are looking at a second war Link."
So the race was on. Just how would they find the orb? And who had that kind of power anyway, to travel through the realms? Midna had barely managed it herself. Just as Zant had been able to hop between the realms without the mirror, Midna had found the way as well. Zant relied on Ganondorf's power, while was able to use the Fused Shadows. It was harder though, much harder. This was why her first attempted failed, when Link first saw her. She had managed to latch on to Link's subconscious mind, which had established a connection as well as allow her to telepathically communicate with Link, which was why he thought her was hearing her wherever she went. Then, after establishing that connection between the realms, she was able to travel on it, in a way, to be transported to wherever Link was. So now a part of Midna was within his mind, so that when the time came she would be able to return to her world. This also meant that they were able to communicate telepathically. It was difficult, because often thoughts that weren't wanted to travel through the connection still got through, for example Link often found out Midna enjoyed the breeze that occasionally came through her skirt. Thankfully, no embarrassing or odd thoughts of Link got through to Midna, most likely because at the moment he was completely focused on the orb, while Midna kept letting her mind wander. However they quickly got the hang of censoring some thoughts so that only what was needed to pass through was sent.
Next came the daunting task of looking for the orb. The sages, through their power, were able to look for any traces of things with Twili origin. It appeared to be difficult, the sages were concentrating hard. Having Midna right there, a thing of Twili origin, probably didn't help. Eventually they discovered that there were traces of something along the lines of what they were looking for in an oases in the desert, one much larger than most. Large enough that people lived in it.
"What you seek lies within the temple of light, built long ago by the people who inhabit those parts. It was a sacred place to worship the goddess Hylia, creator of Hyrule. You must travel there and find the orb, and whoever took it before they make an attempt for the other one…"