Unraveling the Sea (PJO/HoO/SPN)
Andromeda "Andy" Jackson has been through 2 wars and Tartarus, but can she handle hunting? During one of her cases she meets the dashing Dean Winchester and later on his bother, Sam.
Andy learns that her Grandparents were hunters, not vert well know hunters but dam good hunters. When they died in a plane crash, her mother (Sally) leaves the hunting business. But no one can stay away from hunting forever, right? Sally might be retired but her daughter isn't.
Axel (Annabeth) and Andy (Percy) ship name is Andel. @jaybanks101 called it and there's no changing that