The Holy Grail of Eris, Vol. 9 (manga)

Connie has finally solved the mystery of Lily Orlamunde's key and discovered the true meaning of "the Holy Grail of Eris"—a military operation devised by Faris, their neighboring allied nation, to invade Adelbide. Now, the story rewinds to the past, allowing a glimpse into the life of the woman who left the cryptic message. From Lily's meeting with Scarlett, to her childhood with Crown Prince Enrique, to Scarlett's execution…just what did she come to discover? And what drove her to commit suicide?

Volume 9 of The Holy Grail of Eris manga series by Kujira Tokiwa.