When a software developer creates a dating app that a serial killer uses to find his next targets, she’s drawn into a dark world of romance and murder.

A student and a reticent teen first meet at a bakery in the 1990s and try to find each other through the years, as fate keeps pulling them apart.

Renowned 70-year-old poet Lee Jeok-yo falls for a 17-year-old girl named Eun-gyo. Upon realizing his love for the teenager, the poet goes through emotional turmoil and self-destruction, while willing to give up his fame as one of the nation’s most respected literary figures. Involved in the love triangle is Lee's student Seo Ji-woo, a novelist in his 30s who also becomes obsessed with the girl.