AMerci

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.

Rejected Crown Princess To Imperial Cryptographer

It was early in the evening just after dinner that Celeste made her way to Malek's room. She didn't care if he had told her the last time to only come when he called for her. He hadn't called for her at all in such a long time. This time she was determined to get an explanation from him.

"Celeste I thought I told you I would call you when I needed you?!" Malek told as he sighed

"It's been weeks since you last called for me," Celeste told him. "I don't know what suddenly changed when we used to spend the night together every night."

"You know very well that a lot has been happening. Our empire is under attack and so that's what I've been busy taking care of with His Majesty. It's extremely stressful. You know this, so don't be unreasonable!" he complained to her.

"You know I don't think that's what the issue is," Celeste said.

She should begrateful