Amarisa—the young doctor from the modern world—is transported to the early Rattanakosin Kingdom.

On top of that, she finds herself in the midst of the Nine Armies War.

Caught between life and death, she encounters Khem—the fearless commander of a vanguard assault unit fighting on the front lines of the Siamese army.

To her, he is a ruthless warrior who kills without hesitation.

To him, she is a strange woman whose words and mannerisms defy everything he has ever known.

Yet, with every moment they spend together, their hearts start to beat in ways they never have before.