"Owwww," said Danny, settling down between Sam and Tucker, thermos held between his hands.
"Are you hurt?" asked Sam, hand halfway to the popcorn she had abandoned when Danny's ghost sense went off.
"I'm fine. He just grazed me with that new sword that last time, that's all."
"Dude, that's not fine," said Tucker. "Where? I don't see anything. Maybe you can turn down your blurring."
"No, no, there's nothing you guys can do about it. He just clipped off part of my aura, that's all." Danny snuggled back into the couch, still in ghost form. "It'll grow back."
"Wait," said Sam, still frozen. "What do you mean, it clipped off part of your aura? Your aura is made of light. How can he cut part of it off?"
"Oh," said Danny, blinking. "You mean you guys haven't noticed?" Surely he had mentioned it at some point, if they hadn't.
"Noticed what?" asked Tucker. Unlike Sam, he had decided that Danny must not be hurt too badly and was now munching on the snack mix he had abandoned earlier.
"What auras are made of. Here, you've noticed that I get blurry when my aura is bright, right?" He held out his arm. "One sec, let me see if I can make this more tangible." He frowned in concentration. "There! Do you see?"
His friends leaned forward, squinting at his hand. "Are those little lines?" asked Sam. "Little... hairs?"
"Yup! That's what a ghost's aura is made of. They're like, little strings. Usually they're hard to see, because they're mostly intangible and invisible. I mean, we glow, too, but not that much. But stuff that's phase-proof can cut them off. It's kind of uncomfortable, but they grow back pretty quick."
Sam brushed her hand through Danny's aura. He giggled. It felt ticklish, with his aura like this.
"But, why?" she asked.
"It's how ghosts absorb ectoplasm from the air," said Danny. "It's like a filter. That's why ghosts flare their auras before a fight. It isn't just posturing. We're making our auras bigger so we can take in more energy."
"I'd wondered about that," said Tucker. "Still sounds like posturing, though."
"It feels like fuzzy water," said Sam. "Or like those air hand dryers in public bathrooms." She tried to pinch a strand between two fingers. "They remind me of, um, what was that, in biology class?"
"Cilia?" suggested Danny.
"Yeah, that. They hurt when they're cut?"
"Yeah. Kind of like a sunburn, or a carpet rash? Not super painful, just annoying." He let his aura die back and fade into intangibility before switching back to human with a flash of light. "Most of the time I don't use a lot of ectoplasm anyway. What I get through my skin and breathing and eating is fine."
Tucker made a face. "Don't take this the wrong way, but the whole breathing ectoplasm thing... That's kind of gross."
A grin crept over Danny's face. "Oh, ectoplasm is the least one of the least gross things you breathe in every day."
"Nope!" said Tucker. "Don't want to hear it!" He reached for the remote and turned the movie back on as Sam and Danny chuckled.