The seven are no more. After the Giant War, only Percy and Leo remained of the brave heroes. Both of them are having a hard time adjusting to life without war but Percy has it the hardest. Leo has Calypso to help him, while Percy has nobody. So, after making sure that everything at camp was going well, he went to visit his mom and stepdad Paul. When he arrived, he found the police at his apartment. His parents were dead and he had to be put in foster care.
When Pepper finds out that her best friend is dead and her son was to be put in foster care, she begged Tony to let her adopt him. He agrees, thinking it will be an easy task. What him and the rest of the Avengers soon discover, is that it will most definitely not be easy. Because Percy is broken. He's a broken hero.