What is the synopsis of The Injustice to Dou E?

"The Injustice to Dou E," also known as "The Injustice of Dou E" or "The Injustice of Dou E's Death," is a classic Chinese play written by Guan Hanqing during the Yuan dynasty. The story revolves around Dou E, a virtuous woman wrongfully accused of murder after the death of her father-in-law. Despite her protests of innocence and the lack of evidence, she is executed. In her final moments, Dou E vows to reveal her innocence posthumously, leading to supernatural events that ultimately expose the truth and seek justice for her wrongful fate.