Rejected Crown Princess To Imperial Cryptographer

Tanya Edom's position as the Crown Princess is revoked by her fiance, Crown Prince Malek, and she is replaced by his lover, Lady Celeste.
Tanya was head over heels in love with the Prince and wanted to become an Empress worthy of him more than anything. She did everything she could to impress him but her efforts failed to draw his attention in the end

Devasted, Tanya doesn't know what to do, all her life she'd been working toward becoming the future Empress of the Empire, and now her dream had been taken away.
However, after overhearing palace servants gossiping about her demotion, she realizes that her obsession with the prince and being Empress are dreams she should put to rest and try to do something else with her life.

Doing so leads her to get warped up in a conspiracy concerning the crown. She ends up helping the Imperial Army solve a mystery concerning mysterious letters being sent across the empire.