That's right Bucky Barnes has a sister, and not just an ordinary sister. Percy Jackson, better known as Persephone Jackson-Barnes. She is the younger sister to Bucky, and the demigod daughter of Poseidon. Even though she is 6 months younger than him, Percy and Bucky do everything together.
That is, till they meet two boys, Steve Rogers and Andrew Chase-Rogers. Andrew is Steve's stepbrother, and the son of Athena. They meet the Barnes siblings and become best friends, none are seen without the other three.
Andrew and Percy rush off to do quests, and fight wars. Leaving their brothers and families behind, but growing closer together. That is, till they turned 18. World War 2 broke out, and soon boys were enlisting into the Army.
Andrew and Bucky got in right away, and left Steve to struggle to follow. Since Percy was a girl, she had to try harder. Thankfully her older brother, was already in the army, so she got in that way.
Percy quickly rose through the ranks, thanks to the experience of leading two wars, she was more than expected in leading. When Steve finally joined, he learned terrible news, his little brother, best friend and his little sister, had been captured by Hydra.
How will this new super soldier fair? What will happen to the demigods? What will happen to the Barnes siblings?