Killer Instinct by Zoë Sharp is the first book in the Charlie Fox series. Charlie lives in a quiet northern English city, but Charlie often ends up in situations that are anything but quiet! She doesn’t frequent clubs normally, but when a good friend asks her to go with her for a karaoke contest she agrees. This ends up with Charlie having to use her self-defense tactics to save her friend from an angry man at the club. She is then asked to work at the club which leads her into a murder and rape investigation. Charlie is a very troubled young woman who teaches self-defense to women, so when the murderer/rapist comes after her she is well equipped to save herself and her friend.
Charlie is a really likeable female character. As we learn her back story it is easy to understand her motivations and why she is the way she is. There are nine more Charlie Fox books already published with a tenth due out soon.