So the timing and stuff is going to be a bit messed up but imagine that the timeline for Percy Jackson series was before World War two but the demigods of Zeus and Poseidon still battled Hades demigod. Overall, the timeline is just plain messed up, just remember that Percy is older than Steve really.

The next time Percy saw him was when Loki was in a cage. 

He waited until Fury left after the 'ant and boot' talk and made sure he locked the doors before appearing before the shadows.

When Loki turned as he felt a presence he felt shame. Yes he contacted his friend but after three years?

He felt like a horrible friend.

"Sup Lok's." Percy said nonchalantly as he knew the Avengers and Fury were watching.

He also knew Fury was trying to open the door but he's had years of practice to mastering the art of freezing water and when frozen water and machine doors don't exactly mix.

Loki flinched expecting his friend to be mad, "Percy?" Loki said in almost disbelief as if it was weird that his friend answered his call.

"That's my name, don't wear it out." Percy said grinning before his face fell developing into a soldier mask, "It's time isn't it? The deal has come?" Percy asked, his voice low and fearing the answer.

All Loki did was avert his eyes, shoulders dropping, and nodded solemn.

In response Percy's shoulders squared themselves and he looked ready for war, "Loki I made a promise and I'm going to keep it." Percy said seriously.

"Percy I can't have you die." Loki said looking at his friend, almost pleading to let it go.

Percy said in a low dangerous voice, "Do you remember that deal we made five years ago."

Loki nodded not looking at his friend as his heart ached for his son, he missed three birthdays after he was called away.

"How do you think Achilles would react to learn you are dead." Percy asked seriously.

Loki visibly winced loud and clear that didn't take a friend, assassins, or even his brother to know Percy struck a chord, "Let me help you...for Achilles."

Loki's shoulders sagged as if the world was on his shoulders and he was losing, he nodded and Percy looked relieved as he put his hand on the glass cage, "I'll take to the Avengers, explain what's happening. You're not alone Loki, never again." Percy said and instantly unfroze the door as it opened revealing Agents of Shield who pointed their guns at him, Percy clogged the guns with ice and walked by them to the central room.

Instantly when he got in every agent of SHIELD had guns aimed at him. Percy just sighed and looked at Thor who looked surprised that Percy was here, "Thor would you please call them off."

"I'm the one in charge here and when I know you aren't a danger than I will have them lower their weapons." The eye patch man said as the Avengers were sitting, or standing in some cases, and were watching Percy with careful eyes.

Percy's eyes hardened, "I could've killed everyone here with my devine form already." Percy said mostly looking either at Fury or Thor.

Thor's eyes widen considerable as he knew it would've also killed him and quickly said, "Lord Perseus they mean no disrespect."

Of course Thor didn't exactly know that Percy didn't like titles but made sure he didn't let that show, he didn't want to scare the Norse demigod more.

Percy just pinched his nose and muttered, "I hate formality."

"Wait, back up. Did Point-Break just call this dude a Lord. He can't be older than, what? 18?"

"I'll have you know I am older than that. I just chose this form so people don't confuse me with my father." Percy said calmly and amused, he was always chill and a non stuck up god like others.

It's why he got along with Apollo, they were both laid back. He gets it from his father really.

Fury waved a hand seeing how relaxed, and it seemed how true about killing everyone already, and had the agents stand down.

"What were you and Loki talking about?" The man wearing Red, White, and Blue asked. Percy instantly recognizing him as Steve Rogers, Captain America, the man lost in time.

This time Percy stared at Thor, "The Loki right now is doing these things is not him, five years ago he made a deal to have someone close to him live. Now that time has come to bite him in the arse." Percy said

"Who?" Natasha asked from the table who was sitting beside Barton as he had an ice-pack to the head where Natasha knocked him out.

"That doesn't matter right now." Percy said bristly.

"Whose Achilles, from what I know he is a demigod of sorts and that he is long dead." Clint said from where he was

"It does not matter now or ever in your lifespan." Percy said

"What's this deal?" Thor asked not booming loud, hearing the words that his brother was doing this because of a deal was heart wrenching.

Percy looked away and licked his lips in a nervous habit before speaking, "Five years ago, like I said Loki made a deal to save a person he cared abouts life." Percy closed his eyes momentary picture the five year old Achilles, "That deal was made with Thanos." Percy said opening his eyes and staring at Thor who looked stricken with horror.

"Why...why would my brother go to him." Thor asked stuck between anger at Thanos and sad for his brother.

"Who's Thanos?" Bruce asked from where he was.

Percy turned to him, "Someone you don't want to make deals with unless you're desperate." Percy directed the last part to Thor.

"Why couldn't he come to me?" Thor asked sadness filling his heart along with small bits of betrayal.

Percy instantly bristled, "I do not see why he should go to you as you have never helped him when he really needed it, when he learned he was adopted you brushed it off because your lust for the kill was there, he needed you when he learned of his true father, he needed you to believe that he hadn't cut off Sif's hair when you sewed his mouth shut. The list is long and I could continue. Plus, what makes you think you can help when Lady Frigga could not." Percy said his face showing nonce of anger he felt as Thor.

Thor visibly winced reminded of his mistake when he thought Loki had cut his friend Sif hair one night and in Midgardian terms 'beat the shit out of him' into saying he did to stop the onslaught. Thor revenged with sewing Loki's mouth shut with magical string that when Percy found out took him to Hecate and had her and Apollo carefully take out the thread while he cursed Thor's name.

Percy looked happy when Thor winced knowing that at least he felt guilty, "Wait, that's a true story? What about he gave birth to a horse?" Tony asked getting off topic but Percy didn't seem to mind.

Actually it shocked the Avengers and slightly Fury when Percy doubled over laughing, "No, no that was completely off. A joke from Hermes." Percy said laughing at how mad Loki was when he found out and started to chase Hermes around Olympus the whole day, packages were delayed much to Hermes annoyance.

Once Percy regained his breath but a amused smile was on his lips, "Wait, you said Hermes? Like the Greek God Hermes?" Bruce asked

Percy nodded, "Yup, Point-Break as you call him, isn't the only god around. Hey, he isn't even a fully god, just demigod." Percy said

"What, back-up. Greek Gods are real?" Clint Barton asked

Percy nodded, "Along with Romans which is the Greek's, um. Other personalty, and then there are the Egyptians but I'm not going into details there, we have a rocky relationship."

"How come?" Bruce asked

"I'm not to sure." Percy answered honestly

"Can we get back to topic." Fury demanded.

"Yes, one I would like it if you released Loki. Don't give me that look with me here now he won't do anything rash. Two, I'm going to need to send a message to a friend so I need a water bottle. Three, we should probably head to New York seeing how that's where the invasion is going to happen." Percy said in one breath as the others were looking at him, but Percy mostly held his gaze to Fury.

Fury watched for any signs of deception and when he saw none he ordered agents to do as the Greek God had asked for, including releasing Loki as long as he stayed on the ship in sights of one of the Avengers at all times.