My engagement to a strange duke was unexpected

"Entertain me, okay?" A dangerous contract marriage fantasy between a mob lady who wants to avoid death and a mysterious duke who controls the country with a secret organization! Includes a newly drawn manga and a newly written short story by original author Sengoku Kanon! Lydia, the daughter of an earl, is reincarnated into a romance novel she read in her previous life. In order to change her fate of being killed...