Thunder groans outside the window of Salvatrix Valentine's room, who is having one of his worst nightmares in weeks. He’s in a cold sweat and it seems he’ll sleep through it all until his sister rushes in.   “Sally, Salvatrix, get up!” Sabrina Blaine said frantically, shaking him, “Someone’s here!”   The older boy groans and opens his eyes, trying to play it off as though he weren’t just sobbing in his sleep. “Who could possibly be here?” He said, getting out of bed and stumbling as his sibling pulled him hurriedly into the hallway and down the stairs.   The middle child, Samuel, was standing by the door, and the rhythmic sound of a knock was coming from the other side.   “Why didn’t you get it?” Sal croaked, causing Samuel to roll his eyes. “I’ve just mugged a man this morning, I’m not taking my chances.”   The eldest sighed and opened the door, finding a disheveled, rain-soaked person on their doorstep who looked as though they could pass out at any moment.