Disclaimer: I am in no way claiming or profiting from Digimon.

Note: Takes place a few years after the end of Season 2; contains Season 2 spoilers. Sequel to Rainbow Key.

In Nimbusmon's Shadow
Chapter 1

It had been weeks since the digidestined faced the mysterious thief Talya and her digimon, Hebimon. They had failed to retrieve the powerful Rainbow Key which Talya had stolen, and there had been no sign of the girl or her digimon since.

The digidestined needed help, so they called on Izzy. They waited at T.K.'s apartment for Izzy to arrive.

While their digimon sat listening intently, T.K., Kari, Cody, Ken, and Yolei talked about how they might go about finding the Key. Davis and Veemon watched out the window impatiently.

"Izzy said he has some information about Talya," Cody mentioned. "Maybe it will help us."

"He's coming," Davis announced. "And there's someone with him."

Everyone crowded to the window and watched Izzy approach the building, Tentomon in tow. The woman walking beside Izzy was several years older and a little taller than he. She was very slender, with long, straight black hair, and unfashionably light skin.

"Do you think that's the woman he's been talking about?" Kari wondered.

"Tsukiyo? It must be," Yolei said.

A couple of minutes later they arrived.

"Hello, Izzy," T.K. said. "Who is this?"

"I'd like you all to meet Tsukiyo Nishiyama." Izzy presented her as though she were a visiting royal.

The woman bowed to the room. "It's a pleasure to meet you. Izzy has told me so much about all of you."

Izzy continued the introduction. "This is T.K., his digimon Patamon, Kari and Gatomon, Yolei and Hawkmon, Cody and Armadillomon, Ken and Wormmon, Davis and Veemon."

She bowed to each in turn. "Ah, Davis. You're the one who stood up to Myotismon and saved the world. And you, Cody, are the responsible one with the digieggs of Knowledge and Reliability. Kari, Izzy tells me you're caring and compassionate and wise beyond your years. T.K., you're probably the most experienced digidestined there is, and you've cultivated great leadership skills. Yolei, you're the one who's good with computers. Izzy says you're his protégée." Yolei blushed. Tsukiyo came to Ken. "Ken Ichijouji. I've wanted to meet you for years. Izzy says he wants to watch us play chess. I always beat him."

Ken bowed respectfully. "It's an honor to meet you, Dr. Nishiyama. I loved your book Everyday Evolution."

She smiled, showing a hint of shyness. "Please, call me Tsukiyo; 'Dr. Nishiyama' makes me sound so old."

"Now that we're all acquainted," said Izzy, "why don't you show them what you've found, Tsukiyo?"

"Of course." She turned to T.K. "Does your computer have an internet connection?"

"Of course." He set up his computer for her.

She logged on to her e-mail and pulled up a message written in Russian. "Talya: what do we know about her? Basically just her name, that she's Russian, and that she has found her way to the digital world. Now, we all know the digital world is geographically synched with this world, in that digiports will open in predictable locations relative to their origin, so we know she came from Japan or somewhere near here. Assuming she came from Russia, she would have come through a digiport in either Sakhalin or the Kuril islands, Khabarovsk Krai, or Primorsky Krai. My initial search for missing children in those regions turned up no matches, but I realized if she had run away from an orphanage, it wouldn't necessarily have been reported, since that would damage the orphanage's reputation. I looked up the known orphanages in those regions, made some discreet inquiries, and received this response." She scrolled down until an image appeared on the screen: a picture of a familiar redhead. "Natalya Kuznetsova disappeared from an orphanage near Yuzhno-Sakhalinsk about a year ago. According to one of the caretakers at the orphanage, Talya never made any friends and got mediocre grades. The only thing she excelled at was computers."

"That's her," Ken confirmed.

"So now we know who she is, but we still don't know how to find her," T.K. observed.

"We're still working on that," Izzy said. "But we have a couple of theories that could prove helpful."

"If my hypothesis about how the Key works is correct," Tsukiyo explained, "it should be possible to track it while it's being used."

T.K. nodded decisively. "Good. While you and Izzy work on that, I think the digimon should search the digiworld for her."

As Izzy and Tsukiyo left, Tsukiyo looked troubled.

"What's wrong?" asked Izzy.

"Did I act too...stuck up?"

"Of course not. What makes you think that?"

"I'm just worried about first impressions."

Izzy looked at her with curiosity. "You never seem to worry what your colleagues and clients think of you; does it matter what my friends think of you?"

"Yes," she answered softly. "It matters a lot."

A few days later, Izzy and Tsukiyo asked Ken to help them design a device to track the fluctuations the Key caused in the digital world. When they finished for the day, they decided they needed to do something to unwind, so Ken challenged Tsukiyo to a game of chess.

Tsukiyo was looking through her black pieces and Ken's white. She frowned and slowly moved her bishop to an exposed position.

Izzy watched curiously, wondering why she was sacrificing her bishop.

But Ken didn't take the bishop, instead he moved his knight away from it.

"Hmm." Tsukiyo's frown deepened. "He's three moves from checkmating me," she explained to Izzy, "and there's nothing I can do about it."

Sure enough, Ken won in three moves.

"Good game," Tsukiyo complimented as she cleared the board. "I haven't lost in years."

"You had me worried for a while," Ken said, smiling. "Especially after you forced me to sacrifice my queen."

"We need to play again sometime. But I should get going; I've got a lecture to give in the morning. Bye, Izzy. Bye Ken."

Izzy went to the window and watched Tsukiyo walk to the bus stop.

"Ken, can I ask you something?"

"Sure."

Izzy closed his eyes. "I've never been good at...dealing with people. Socially, I'm a complete idiot." He sighed. "How do I find out if she feels the same about me as I feel about her without letting her know how I feel about her?"

"Why don't you just ask her?"

"Because if she just wants me for a friend I don't want to do anything to risk losing her as a friend. Do you know what I mean?"

Ken nodded. He knew very well.

Izzy glanced at him and saw a look on his face he didn't understand at first. Then he laughed.

Ken glanced at him curiously. "What's so funny?"

"Who is she?"

"Who?"

"The girl you were just thinking about." Izzy realized he was being presumptuous and rephrased his statement. "The person you were just thinking about."

"No one," Ken claimed unconvincingly.

"Someone I know?"

He coughed politely and hoped he wasn't blushing. "Maybe you should take Tsukiyo to a restaurant or on a picnic without mentioning the word 'date.' That way, you can see if she acts like you're on a date, and if she doesn't then it wasn't a date and you can still be friends."

"That's a good idea. I'll have to try it. You should too."

Ken nodded, then realized Izzy had tricked him into admission. He tried to cover. "Yes, if I ever happen to want to know if someone likes me, I will have to try that."

"Just tell me who it is," Izzy said with an amused half-smile. "Someone I know, obviously, otherwise you would tell me."

Ken blushed a deep red. "I don't want her to know. Not yet. I want to wait until the right time."

"I understand. Why don't you just tell me a nickname for her, so we can talk about her without risking her overhearing?"

Ken thought about it for a moment. "Ever since this dream I had about her, I've been comparing her to wisteria."

"So she's purple, fragrant, and grows on vines?"

Ken rewarded the joke with a wry smile. "It's called a simile, Izzy. It's a poetic convention."

"I understand. I think Tsukiyo's name is very appropriate; she reminds me of moonlight."

Ken mentally agreed that, poetically speaking (and he was a closet poet), Tsukiyo was a river gently rippling in the moonlight, while Yolei was a wisteria vine in full bloom on a bright morning.

The following day, Izzy rather awkwardly suggested to Tsukiyo that they go out to dinner while they brainstormed ways to stop Talya from using the Key once they found her. She agreed, though she insisted on paying. Izzy wasn't sure whether that was a good sign.

"If I'm right that Talya becomes Nimbusmon through the same process that a digimon digivolves to the next level, would there be any way to keep her from digivolving?" Tsukiyo inquired as she poked at a plate of steaming fried calamari.

Izzy thought about it as he twirled spaghetti around his fork. "No easy way. Unless we found a functioning control spire."

"What's a control spire?"

"Control spires were towers built by the digimon emperor that prevented digivolution."

"Who is the digimon emperor?"

He realized he'd never told her about that. They talked about the digital world all the time, but usually only discussed the science of it, rarely the history, though he had told her some of his adventures with the older digidestined. "It seems like so long ago," Izzy mused. "Time certainly moves in strange ways sometimes."

"You should read my book Speed of Thought. But tell me about this digimon emperor first."

Izzy smiled at her impatience. He was going to tease her. "When I first went to the digital world, we could only go there if something was wrong, something we needed to fix. But then, a few years ago, a human appeared in the digital world who had a new, more powerful digivice that could open a digiport from any computer. We didn't know how he got it, or where he came from. He built the control spires and created dark rings to enslave digimon."

"Like the dark gears you had to deal with?"

"Exactly. Same principle. This human called himself the digimon emperor. He was highly intelligent, but used his genius for evil. T.K., Kari, Davis, Yolei, and Cody were chosen by the powers of the digital world to oppose him. They were given digivices as powerful as his, and their digimon were able to armor digivolve, which wasn't affected by the control spires. But the emperor seemed invincible. He somehow created his own digimon based on the most powerful parts of other digimon, which he fittingly named Kimeramon. It destroyed everything in its path, and all of their digimon together weren't enough to stop it. Davis found the Golden Digiegg, which allowed Veemon to digi-armor digivolve to Magnamon, but even he wasn't powerful enough to destroy Kimeramon until the digimon emperor's own digimon turned against him and sacrificed his energy to aid Magnamon."

Tsukiyo listened, her eyes wide. "Why did the emperor's digimon betray him?"

"The emperor was cruel even to his own partner. The digimon hoped he could not only stop his partner from destroying the digidestined, but somehow save him from evil. And he did. It was his death that made the emperor see the error of his ways. He left the digital world, and we all hoped he would never show his face around there again." He examined Tsukiyo's expression carefully. Did she suspect the truth? She knew about Ken's disappearance, and surely it couldn't have escaped her notice that he'd made no mention of Ken in the entire story. But she didn't seem to have made the connection yet.

"Did he ever go back to the digital world?"

He struggled to keep a straight face. He'd keep dropping clues until she guessed. "I've told you that digimon come back as digieggs after they die."

She nodded. "So the emperor's digimon was reborn. You've also told me digieggs can appear in our world, and nothing guarantees the emperor was even reunited with his digimon, so you haven't answered my question. Except you seem to think you have...so the answer must be affirmative." She kept staring at him, and he could see the complex mechanisms of her mind working to unravel this enigma. Her eyes dropped to the table and she sat back in her chair. "Wormmon," she whispered. "Wormmon was the emperor's digimon, and the emperor was none other than sweet little Ken Ichijouji, boy genius." She flicked her eyes up at him. "Wasn't he?"

Izzy nodded. Tsukiyo laughed. "It makes sense, though. His disappearance, his even-more-mysterious reappearance, the rumors that he returned with amnesia, which you know is nearly always caused by psychological trauma." Her smile disappeared at that thought. "He must have endured so much. No wonder he's so dedicated to the digital world now; he's a traitor to evil. Traitors make the most dedicated and dangerous of foes, not to mention the most bitterly hated."

An hour later, Izzy walked Tsukiyo to her apartment. She stopped at her door and turned to him. Her shyness showed itself again, and she lowered her eyes to the floor as she spoke. "I had a wonderful time tonight. I hope we do this again soon."

"Next time, you can pick the restaurant," Izzy said in a flimsy attempt to lighten the mood.

Tsukiyo laughed nervously. They stood in awkward silent for a moment, neither looking directly at the other. "Goodnight," Tsukiyo said, then entered her apartment.

"Goodnight," Izzy replied before her door closed.

Tsukiyo went to her window and watched Izzy walk away.