Trapped in a free cage

Upset at her best friend's death, vanessa, reads her book as her last wish. However, on that fine rainy morning when she visits her friend, Vanny gets murdered and transports into the novel. Bad news is that it's an incomplete dark romance novel, good news is that Vanessa knows more than what is written and she's got time. Can she survive as the best friend of the main character?, And who's this second person who also got trapped along with her, and why is he sooo cute~