In a warlord’s mansion, the ninth concubine is seen as a vain, useless woman who only cares about painting her nails. Her rivals mock her, and the warlord pays her little attention. But behind her elegant appearance, she is a master of revenge and strategy. Using nail polish as her hidden signal, she gathers evidence, exposes conspiracies, and takes down anyone who tries to destroy her. She quietly controls the entire mansion, becoming the most powerful woman in the house.