Castiel saw the bruises.

It was completely unintentional. He had gym last period and he always had to get dressed quickly before the basketball club met and the gym teacher had him stay after class to discuss his sudden decrease in endurance (which wasn't his fault- he was beginning to think he'd cracked a few ribs) and he'd had less time to change today.

Castiel was the first person to walk in for the club meeting. He always was, since he hung out in the courtyard so often. Nathaniel had just reached for his shirt when he heard footsteps behind him.

And of all people, it just had to be Castiel.

Just his luck.

Castiel wasn't glaring at him, which was a first. Castiel was just staring at him. He looked like he'd about to make some biting remark, but he'd cut himself off. Now his mouth hung slightly open, and his expression ranged from shock to anger to confusion.

Finally, he shook his head, closing his eyes and slipping into that indifferent mask of his.

"You're not going to ask?" Nathaniel asked, sliding his shirt over his head. He was surprised at how steady his voice was, considering how quickly his heart was beating.

"Hey, no, I want to ask," Castiel said, frowning. "But I think if I do you'll just give some stupid answer like 'oh, I just fell down the stairs-'" His voice went into a mocking falsetto as he said that, and Nathaniel cut him off with an indignant (and embarrassingly high-pitched) "I don't sound like that," but Castiel kept going.

"-And quite frankly, I don't wanna hear it. So I'm just gonna change, forget I ever saw this, and leave. But, Nathaniel-" he said, suddenly serious. "I hate you."

"What else is new?" Nathaniel grumbled.

"But I don't-" he groaned, muttering something under his breath.

"What was that?"

"I said I don't want you to actually get hurt," Castiel said, a bit louder.

"Mhmm. That's why you start fistfights with me in the hallways and pull my chair out from under me when I'm about to sit down and fill the entire student council room with flowers on April Fools' day so that I have to be sent home because I have allergic reactions so bad that I can't breathe."

"Hey, no, that last one was unintentional. I didn't realize your allergies were that bad. I thought you'd just be a bit puffy eyed and sniffly the rest of the day." He paused for a bit, looking at his feet. "Sorry again for almost killing you by the way."

"I almost believe you," Nathaniel scoffed, glancing at the clock on the far wall. "Oh, shoot," he said, grabbing his bag and shoving past Castiel. "My dad's gonna kill me..."

Castiel stared after him, frowning.

Where had those bruises come from?

It's not because you're worried, Castiel told himself as he followed Nathaniel home, ditching the basketball club. Just curiosity.

Nathaniel walked into a house at the far end of the street. Castiel raised his eyebrows- that was a really big house.

Or maybe it was just because he'd grown up in an apartment.

He sat outside the house, under one of the windows, hidden from view by some nicely-trimmed hedges.

He heard shouting from inside, the voice of a man he hadn't heard before- Nathaniel's dad, he assumed. He couldn't quite make out the words, but it wasn't concerned parent yelling; the yelling was angry.

The yelling stopped suddenly; Nathaniel was saying something back, probably.

And then something glass shattered from inside the house.

Castiel launched himself up, peeking through a gap in the window curtains. There, on the ground, was Nathaniel, surrounded by broken porcelain and with a huge gash on his forehead. He wasn't unconscious; he was propping himself up on his elbows.

Castiel had seen enough.

He ran around to the front of the house. The door was unlocked, luckily- Nathaniel must have forgotten to lock it, or maybe he hasn't had time to when his dad had started yelling.

Yeah, he hated Nathaniel.

But not enough to let him get killed.

He followed the sound of the yelling and found himself in a kitchen. Nathaniel was still lying on the ground, his father holding a glass bottle and standing over him threateningly.

"Hey!" Castiel yelled, running over and pulling the man away from Nathaniel. Belatedly he realized that Nathaniel's father was a good foot taller than him and probably a lot stronger. He pushed Castiel off with very little effort, and he fell to the ground with a grunt.

He rolled out of the way just as the bottle came sailing down- not at Nathaniel this time, but himself.

Putting his weight on his arms, he kicked his legs out, hitting the man's shins and pulling his legs out from under him. On the way down, Nathaniel's dad hit his head on a counter. He landed on the tile floor, dazed but not out yet.

Castiel helped Nathaniel up. The two ran out of the kitchen, glass shards crunching under their shoes, and out of the house, and down a few blocks until they were sure they were a safe distance away.

They stood there for a moment, catching their breath.

"Hey, Castiel?"

"Hm?"

"I forgive you for the flower incident."

"About time."