Based on an anonymous tumblr prompt.

.

.

Clockwork kept many things in his tower. Wonderous things. Dangerous things. Curious things. Impossible things. Things that he just wanted, for some reason or another.

In one room, he kept a mirror. He kept many mirrors, in many rooms, and not all of them showed simple reflections. Some of them did things that even ghosts would find uncanny.

"What does this one do?" asked Danny, inspecting the cloth-draped frame.

"It shows you a might-have-been. What you never knew you wanted and can never have."

"That... doesn't sound great, honestly," said Danny. "Who'd want that?"

"Very few people. In fact, it drove several to madness before it came under my care," said Clockwork.

"And... you want me to look at it? Really? I mean, I haven't exactly had the best track record with going crazy and all."

"It is important to know yourself," said Clockwork, putting a hand on Danny's shoulder. "You are forewarned. You are forearmed. I am here. No matter what you see, it will not affect anything in reality."

Danny nodded slowly. "But it shows something that might have happened?"

"Yes," said Clockwork. "But not necessarily something likely."

Danny took a deep breath. "Okay. I'm ready."

Clockwork reached over Danny's shoulder and pulled the cloth on the mirror away.

At first, Danny thought the mirror was just showing him an ordinary reflection. Then he noticed that there were two of him. He tilted his head. Sure, he wanted to be able to duplicate himself better and more consistently, but that was just it. He wanted that. He knew he wanted that. It wasn't a mystery.

So, that couldn't be what the mirror was trying to tell him. There had to be something else.

Dani leaned into the frame. Oh, was this about her being closer, then? He did want that, but... Again, he'd known he wanted that for ages. So, what...?

One of his doubles tweaked Dani's ear, and she laughingly reprimanded him, but...

But that wasn't Danny's name, silently passing her lips.

He stepped closer, examining the reflection more intently. His second reflection... it wasn't him at all. Looking closer, he could see small differences between himself and this almost-double. Even if he assumed the image wasn't flipped right to left... He had a scar Danny didn't, was missing others, the pattern of his freckles were different, his eyes had a slightly different distribution of color in the iris, the way he was holding himself wasn't quite like Danny did-

There was a flash of light as the half-ghosts in the mirror transformed. All three of them. With this, it was even more obvious the second boy wasn't Danny, although the first was, or a duplicate. He was a whole different person. The color of his aura was different, warmer, the constellations his glowing freckles described were different, his hair licked with faint fire at the ends, and most importantly, his symbol was different.

"I... a twin..." he breathed, breath fogging on the glass. When had he gotten that close?

Something he didn't know he'd wanted. A person who would really, truly, understand what he was, who he was, what he was going through, like even Dani and Clockwork couldn't.

The family in the mirror smiled sadly at Danny and turned away, just in time for Clockwork to let the cloth fall to cover it again. He took a deep breath that was only a hairsbreadth from becoming a sob.

A tear traced its way down the curve of his cheek. He forced himself to laugh.

"I guess... knowing myself... I guess this means I'm lonely, huh? And even with all this- I'm sorry, I must seem really ungrateful. You're-" He cut himself off, not wanting to break down.

Clockwork waited quietly.

"You guys are all great," Danny finished. "It's just..."

"I think that everyone longs for someone who can understand them completely at some point," said Clockwork.

"You think?" said Danny, the joke coming a little easier this time. "You don't know?"

"I don't read minds, Daniel. Now, shall we go? Reflection is all very well and good, but it doesn't do to dwell in them.