Think about it: Santa sneaks in during the dead of night. He steals cookies, drinks some milk, maybe tracks ashes all over the living room. Yeah, he leaves presents, but maybe that’s just a cover for more nefarious behavior. Who knows…besides Santa himself? The darker side of Santa shows up in two of the Christmas stories in this collection, “Doubting Thomas” and “Rehabilitation.” Real criminals—the scary kind—make an appearance in “Snow Angels” and “Substitutions.” And just to add a bit of the proper Christmas sentiment, “Nutball Season” closes the volume—with a not-so-sinister Santa, a little boy, and a cop stamping his feet in the snow on Christmas Eve.