The Vengeful Chef's Recipe

Ivy and Iris Doyle were born twins. Iris came out with crimson eyes and was thrown out of the house for it as an infant. Ivy was born blind and stayed, and years later she was married off, and her husband and his men pushed her off a cliff. Iris had grown up elsewhere and become head of Umbral, the assassins' order, and she came back for her sister. She entered the Doyle house wearing Ivy's identity, dead sister returned, and started tracing what had happened. Her cooking was good enough to take her into the imperial kitchens and win the title of Imperial Gastronome, which put her near the court and near the people who would talk. The stepmother's daughter, who had a hand in Ivy's death, was competing for the same post. From the palace she worked outward, through the quarrels between the legitimate line and the concubines' children, into a conspiracy reaching past the family entirely. The crown prince came to trust her. What she found there touched a war that was already gathering, and she used the position she had earned to put it down.