Trick or Treat by K.M. Rogness

TRICK OR TREAT: AN EROTIC HORROR
Scarlett was a good girl, always followed the rules and did what she was supposed to, until one night everything changed. A night out with her friends, and one of them ends up dead. Now a secret is kept within their sacred group, but as the year passes, each one either vanishes or ends up dead…except her. When strange things start happening around her, she begins to panic and worry that she’ll become the next one to meet her fate. When Halloween comes around, the anniversary of the death of her friend, she finds herself held captive in the hands of four dangerous, masked strangers, and they’re out to make this Halloween one that she’ll never forget.