Hemlock Island by Kelley Armstrong
I don't read a lot of horror, but once in a while once grabs my attention. Hemlock Island revolves around Laney Kilpatrick, an English teacher and thriller author who is recently divorced and is grieving her sister who lost her battle to cancer. She is raising her 16-year-old niece, Madison, and reluctantly renting her vacation home on a remote island to strangers. Things get out of control when the renters call her in the middle of the night to inform her that there are blood and nail marks all over the guest room's closet. Laney goes out to the house with her niece Madison. Her ex-husband, Kit, also shows up with his sister, Jayla. And then, we have Sadie, a former friend from high school, and her brother, Garrett, who is now a cop. There is so much tension in the group, but we gradually learn about their relationships and secrets. Then one of their group goes missing - and...