Rachel Dawes (Maggie Gyllenhaal)

The Dark Knight
Rachel, by this time, is the assisstant DA to Harvey Dent, a man who is challenging the mob in Gotham in a legal way. She has also started dating him, creating a love triangle between herself, Dent, and Bruce.

When the mob hires the Joker to kill Batman out of desperation, the Joker says he will kill people until Batman reveals his identity. Harvey, realizing how important Batman is, says he is the Batman. When Joker tries to kill him, the real Batman and Commissioner Gordon capture him.

But during this time, Joker manipulates two cops into bringing Dent and Rachel to different buildings in the city. There, both of them are tied up with bombs and gasoline surrounding them. Joker reveals the locations to Batman and the police, but swaps the locations, making Batman go after Dent and Gordon go after Rachel. Batman gets Harvey out with half of his face burned, but Gordon is too late to save Rachel, who dies in an explosion.

Earlier, Rachel left Alfred a note to give to Bruce, leaving it unsealed so Alfred could also read it. It said that because she felt Bruce wouldn't be able to give up Batman, she was going to marry Harvey. When Alfred goes to give it to Bruce after her death, he burns it instead when he hears that Bruce was sure she would've waited for him.