When April needs help with schoolwork, Donatello will always be there. Numbers are easy. It's life that's hard.

It started with a text message, as always. Calculus test tomorrow. PLEASE HELP.

"Going over to April's," he said to his brothers.

"Have fun," said Leo, not taking his eyes off the TV.

Donnie left the tunnels behind for the light and noise of the city. New York at night was a nasal cacophony, car exhausts and cooking and garbage and people. If the sewers were a refuge, they were also a prison. Here on the rooftops, for a while, he could be free.

He lost himself in the journey, run and leap and land and run again. The thrust of muscles and the impact of feet on concrete and tile, the shock of it through his body, the tender pull of scars old and new. He paused on the edge of the rooftop. Across the alleyway the light was on in her room. He leaped across, landed on the fire escape.

April threw open the window. "Donnie! You're a life saver."

"That's me. Always here to save the day." He tucked his bo out of sight in the corner, sat on the windowsill, swung his legs over and into her room.

It was nice to be welcome.

Donnie's arm was on the bed behind her. She could feel the warmth of it through her shirt. He was leaning over her shoulder, intent on the book, one finger tapping the page to emphasise his point. She turned her head slightly, to find his cheek inches from hers. Under the curve of his jaw, the muscles in his neck stood out beneath the mottled green skin.

And he had no idea how close they were. A slow warmth spread in her belly. He was always at his best when explaining something, when the intellectual side of him was firmly in control. There was none of the awkward, unsure Donnie then. If only-

I wonder what would happen if I kissed him.

"Does that make sense?" he said.

"What? Uh, oh, yes. Right." Damn, she didn't have a clue what he had just said. "Um, at least-"

They both froze at the sound of footsteps in the hallway.

"Oh my god, Dad will have a fit if he finds you in my room at this time of night!" she whispered.

The door handle moved. There was a soft sound and Donnie was gone from her side. The ruffle around the bottom of her bed rippled. She sent a silent thank you to ninja stealth.

The door opened and her father poked his head through. "April? I thought I heard you talking to someone."

"Nope. Just, um, the radio."

He looked down at the book in her hand. "Isn't it a bit late to be studying?"

"Big test tomorrow." She hoped her grin didn't look as fake as it felt.

Her Dad walked over to the window and peered through. "It's a bit late for visitors, April."

"Of course." She tried to look as if there wasn't a ninja turtle currently hiding under her bed. She knew he appreciated the turtles, but there were limits. Her bedroom near midnight would definitely count as a line not to be crossed.

"Any visitors." He turned and frowned down at her.

"Yeah, Dad, I know." No need for him to say who he meant. Who else came and went via her window at night?

He glanced outside once more. "Well, I think it's time for bed now."

"Sure. Night Dad."

"Goodnight, April."

The door closed behind him. April waited until she heard his footsteps moving away, then breathed a sigh of relief. "You can come out now," she whispered.

A purple plastic pony head peeped out from under the ruffle around the bottom of her bed. She squeaked, then slapped her hands over her mouth. The pony's body followed, dwarfed by the enormous green hand wrapped around its middle, bouncing it along the carpet like a demented rabbit.

"What are you doing?" she hissed. "Put that down!" She yanked the horse out of his grasp, blushing furiously.

Donnie's head emerged from under the bed. Dust patterned his skin. "It's like a toy graveyard under here. Why are there so many horses?"

"I liked horses!"

"There are plastic cowboy boots."

"They're cowGIRL boots, thank you." She grabbed his arm and hauled. "Now get out from under there!"

He emerged, grinning, and her blush threatened to set her face on fire. "New rule. Stay away from my bed!"

She caught the look on his face, and just like that, the easy camaraderie was gone. They were back to the awkward fumbling. She was weary of it. But how to climb this unscalable wall of unsaid feelings? How to reach a place where they were both comfortable?

His feelings were clear. It was her own feelings that she struggled with.

She sighed and let go of his hand. He stood and they faced each other, his hands wrapped around the leather harness over his shoulder, his eyes on the floor.

"Well, I'd better-" she caught herself before saying go to bed. "-call it a night."

"Sure. Good luck with the test tomorrow. Just remember the rules of derivatives. It's easy."

"For you."

"You can do it." He threw open the window and swung himself through. "Good night, April."

"Donnie." She leaned out, wrapped her arms around his neck. "Thank you."

She was rewarded with the tentative, gentle touch of his hands on her back, the catch of his breath.

"You're welcome, April."

He picked up his staff and was gone in one smooth leap.

He watched her silhouette move about the room, playing the evening over in his head, trying to assign meaning to every gesture, every word. But it was too hard, too open to interpretation and he failed, as always, to draw reliable conclusions from her actions.

But there had been one moment, leaning over the book, listening to her stumble through an equation, when he'd glanced aside and realised how close they were. Her lashes, the length of them, fascinated him and he'd lost the thread of her voice. The freckles on her cheek were a puzzle he couldn't solve. He longed to reach across and brush the hair back from her eyes with his fingers. To touch the warmth of her skin.

But instead, here he was on the rooftop, waiting for her light to go out. Again. An urge rose, to go back, to knock on the window, to ask the question that bothered him late at night. Is it who I am, or what I am? Tell me.

The light in her room went out. He turned and ran, across the rooftops, under the hazy sky, back to the sewers, their refuge, his lonely prison.