Percy Jackson meets Harry Potter

Attacked

"We know you aren't normal wizards."
Percy's heart nearly stopped. How had they found out? He was on the verge of blurting out everything when Nico stepped on his foot.
"We're American." He said cautiously.
"We're not going to be like other wizards you've met."
"That's not what I mean. You know it. You have to tell us the truth sometime."
Percy suspected Harry had no clue what was going on. He had a bewildered expression on his face. Percy guessed Hermione hadn't filled him in on what she had discovered.
"Listen, we just... wait a minute... have you guys been spying on us?"
Hermione bit her lip, and wouldn't meet their eyes.
"You have!" Percy said incredulously.
"We thought you trusted us! And we trusted you."
"Percy, I'm sorry." Hermione said.
"We shouldn't have pried. It's your own business. I... I swear I won't spy on you any more."
"Why should we believe you?" Percy said bluntly. He hadn't meant for it to sound so harsh, but he was upset.
"I mean... you won't believe us." He told her a little more nicely, when she winced.
"Percy... I... I'm sorry. I just can't ignore the obvious facts. You don't have to tell us. Come on, Harry."
They turned to go, Harry looking like he still needed some time to process what just happened. Percy felt a twinge of remorse.
"Guys, wait." He said before he could stop himself.
"It... it's alright. I'll tell you something. I'll tell you about Annabeth. Not now. Later. Meet us in the common room. We have to... do something."
Hermione smiled.
"Thanks." She said simply. They turned again to leave.
"Hermione?" Percy heard Harry whisper.
"What just happened?" Then Percy grabbed Nico and Leo's arms and pulled them to the Divination classroom.
Professor Trewlany had no students at the moment, which was just what they wanted. They walked in, and Trewlany looked puzzled to see them.
"My dears, what can I-" she stopped, and Percy braced himself. She spouted the prophecies she hadn't said yet, and all of Percy's life threatening quests passed in front of him. He nearly lost it when he saw Tartarus again, but he was ready this time. Finally, the prophecies ended, and Trewlany collapsed to the floor. Percy and Leo helped her sit up.
"My dears, what just happened?"
"Oh, nothing, Professor. You were just taking a nap. Sorry we woke you." Nico improvised, and the three exited leaving a very puzzled teacher on the floor.
They made their way to the common room.
"Password?" The Fat Lady asked.
"Afroditis pagoni." Percy said. The portrait swung open. They found Harry and Hermione sitting in two of the comfy armchairs.
"Alright. I promised to tell you about Annabeth." Percy said, before he could lose his nerve. Talking about Annabeth had been very difficult for him these past few months.
"She's my girlfriend. She went missing a couple of months ago. We have some... friends... looking for her and they found some evidence that she... may be being held here. Annabeth's... the most wonderful girlfriend I could ever hope for. She never stopped looking for me when I went missing, and I want to do the same, but..." he realized he had almost spilled some sensitive information. He had already shared some delicate content: that he had gone missing before.
"When you went missing?" Harry asked.
"What happened then?"
Percy shook his head.
"He said he'd tell you about Annabeth. We're not gonna share anything else. Yet." Leo interrupted.
"Yet?" Nico whispered, possibly loud enough for the others to hear.
"Yeah." Leo lowered his voice so Harry and Hermione definitely couldn't hear him.
"Chiron said we should tell them. It's dangerous, but we've gotta tell them eventually. If we don't, they'll probably just figure it out on their own." Percy agreed wholeheartedly. Hermione was pretty smart. She was already close to the truth. Give it a week or so, and she would know.
"Anyways, we aren't sharing yet. Maybe soon, but not now." Harry and Hermione both looked a little bummed at the small amount of information, but didn't argue.
"We actually have something to show you." Harry said unexpectedly.
"We do?" Hermione asked.
"Yeah." Harry pulled out a small bundle of cloth.
"Harry!" Hermione exclaimed. "Are you sure?" Nico stood suddenly.
"What is that thing?" He said.
"Nico, what's wrong?" Nico hesitated, and glanced at Harry and Hermione. He took a deep breath like he was about to do something he would later regret.
"Αισθάνομαι το πνεύμα του Θανάτου σε αυτό το πράγμα." He said in rapid fire Greek.
(Translation for the people who aren't fluent in Greek: "I sense the spirit of Thanatos in that thing." According to Google Translate at least.)
Hermione and Harry gaped at him.  Percy, Leo, and Nico ignored them.
"τι νομίζεις ότι σημαίνει?" Percy questioned.
(What do you think it means?)
"Δεν έχω ιδέα , αλλά δεν μπορεί να είναι καλό." Nico responded grimly.
(No idea, but it can't be good.)
Switching back to English, Percy turned back to Harry, "What is that thing?"
"Y-you just spoke in fluent Greek. H-how...?" Hermione stuttered. Nico gave her an evil look. She swallowed.
"Never mind."
"It's... it's an invisibility cloak. It... makes you... well you can guess." Harry replied, staring at Nico and Percy with a slightly dazed look.
"I'm assuming you aren't going to tell us what you said?" He guessed.
"Harry, if they wanted us to know what they were saying, they would've said it in English." Hermione scolded.
"How does the invisibility cloak work?" Leo asked.
"Um, I don't actually know." Harry said. Leo looked disappointed.
Harry unfolded the cloak, and shook it out. He pulled it over himself.
"Woah!" Leo said. "That's pretty cool."
"Yeah!" Percy agreed. "That works just as good as Annabeth's..." he realized what he just said. 'Well, they are wizards. A magical item isn't a huge surprise to them.' He thought.
"Annabeth's invisibility cap." He finished.
"Annabeth's a witch?" Hermione asked politely.
"Uh, yeah!" Percy lied.
"And I bet she'd love it here." He added quietly. Hermione put a hand on his shoulder.
"We'll try and find her before Christmas break." She promised.
"You'll help us?" Percy asked.
"Of course!" She exclaimed.
"Yeah." Harry agreed. "That's what friends are for." He shot a grin at Percy. Percy returned it.
"Thanks bro." Percy said.
"Anytime, er, bro." Harry replied awkwardly. Suddenly the painting burst open.
"Harry! Hermione!" It was Neville. His face was red from exertion.
"Come quick! D-death Eaters
a-and. Just come please!" He gasped.
"We'll come too." Percy said quickly.
"No!" Harry said immediately. "I don't want you getting hurt! If Voldemort sent them, it's me they're after. I don't want anyone risking their life for me." Hermione glowered at him.
"Well you aren't going to keep me from helping you." She snapped quickly.
"Hermione I can't ask you to risk yourself for me..."
"Then don't ask. I'm doing it because I'm your friend. And they're your friends too. If they want to help, let them." Harry sighed and, with a pained look, nodded.
"Just be careful you three. Death Eaters are no joke."
Percy, Leo and Nico just exchanged amused glances.
"Well? What are we waiting for?" Percy said. His hand went to his pocket and he brought out Riptide. Hermione gave him a funny look. Nico elbowed him so hard, he almost dropped his
pen-sword.
"Geez, Nico." He muttered.
"Sorry." He said and slipped Riptide back in his pocket. He grabbed his wand.
"Let's go." Harry said, pulling out his own wand. They rushed out to face the Death Eaters.