The 3rd Angel (Pjo x TMR)

Nico Di Angelo is just having another normal day at Camp. He was in front of the forest when he saw an unknown girl jump out of the woods. She seemed familiar, and it turned out she was is sister. Not Bianca, no, she was gone. But as happy he was to see her, he still had no idea how she came in, when she came in, or anything else. It might've just been Hera..or was it something worse?