Percy wasn't a fan of concerts. The music and people were too loud (reminded him of the constant inhuman screams that became background noise in Tartarus—and in his nightmares, of course) and there were way too many people. He'd promised Grover he'd come with him though, even if he wasn't that big a fan of the mostly instrumental music made with weird, archaic instruments and the "nature" sounds the singer tried to imitate.

Still, after the third time the guy at the psaltery (a weird string instrument that kind of resembled a guitar—Grover tried to give him a crash course on the instruments on the way here but gave up when Percy kept pronouncing every single one wrong) completely butchered the poor strings Percy lied and told the satyr he was going to find the bathroom. He could only hope there was a big queue that would keep him there until the end of the concert.

So he went and found the bathroom almost immediately, and he was grateful he didn't actually have to go because it looked absolutely fucking disgusting, so he resigned himself to wait for a few songs and then go back to Grover when something caught his attention. He had to squint and subtly shuffle a bit closer to make sure, but yes that was definitely a fucking empousa. Fucking fuck, can he really not get a break? At least he'll have an excuse for what took him so long at the "bathroom".

The empousa was sporting a mini dress in a color that did no favors for her donkey leg, but he figured the guy she was currently flirting with wouldn't mind, even if he could see it. Percy got out Riptide and was about to get closer to confront the monster when she took the guy by the hand and went even further into the dark, going behind the structure that made up the little shop where they sold the band's paraphernalia—it was a bit deserted, no wonder why (their biggest object was a wood-looking sculpture of the band's main singer, good gods).

Percy cursed under his breath and followed, certain he had not imagined the wicked grin on the monster's face; she was probably getting ready to finish him off.

Sure enough, as soon as he rounded the corner, he saw the empousa bent over the guy's immobile form on the floor. Percy snarled and went to get closer to swing Riptide when he froze—he knew that guy. Fuck, he was in his history class. It was Ben, one of the nicest guys Percy had met, the one who had helped Percy study when Annabeth wasn't available or got frustrated with him because history had always been one of his worst subjects (too many numbers and names and countries and why was it important to learn all that shit?).

He felt his blood boil. He hadn't been this angry in a while, and to top it off, the empousa clearly heard his aborted movement and looked up—Percy almost threw up on the spot (he suddenly realized he had never actually seen the result of an empusa drinking blood). Ben's neck was mangled, there was blood dripping from the empousa's grinning teeth, which suddenly turned into a grimace when she noticed his sword. She quickly got up and took a few steps back, taking advantage of Percy having to actually swallow down his nausea. They stared at each other.

"My, my, is it the demigod I think it is?" the empousa suddenly purred. "I had expected the great Percy Jackson to be more…" she looked him up and down, "powerful."

"Fuck you," Percy snarled. He was breathing heavily, thoughts moving quickly through how best to get Ben help (how he hated not to have a fucking phone).

"He was really easy, you know?" she taunted him. "He was all too willing to believe everything I said, and didn't even think twice about following me here," she sighed in faked sadness. "I kind of wanted more of a challenge," her eyes glinted, "do you have another friend I can try?"

He was so mad he felt like he was going to explode. It almost felt like a panic attack; he was panting, he felt warm all over, and he just wanted the feeling to stop—he focused on the monster in front of him and exhaled.

The empousa suddenly was—not there. Percy stood dumbfounded for what felt like an eternity, blood and golden dust covering his skin before he turned away and threw up. He had just… the feeling of blood boiling, boiling because of him. It was unnerving. The sight of the empusa's body just imploding because her blood combusted because of his anger, gods, what was wrong with him?

A sudden gurgle snapped his attention back to the body on the floor. Ben. Godsdammit, how stupid can Percy be? He rushed to him, put pressure on the wounds, and called for help while he tried to carry Ben around the corner, to get a phone or someone to help or something.

Eventually, someone called 911 for him while he tried to keep Ben conscious. Grover found him before the ambulance got there. Percy knew he was moving but his mind was not there with him, stuck in the image of an exploding body.

He didn't go in the ambulance with Ben.