Need to find this book: Winter, mysterious call, disappeared brother, small town

[mar]

The book I am looking for starts with a girl getting a mysterious call from someone that is very confused and does not seem to know where they are. The girl's brother was missing and there are c

[mar]

The book I am looking for starts with a girl getting a mysterious call from someone that is very confused and does not seem to know where they are. The girl's brother was missing and had a scar in his hand. Crimes start to come up that start being attributed to the mysterious boy. That boy also did not have genitals. The girl kept getting calls from the mysterious boy. It was based in the winter.