Rachel Elizabeth Dare

Rachel Elizabeth Dare, unlike other prominent members of the series, is born of two mortal parents. However, what sets her apart from normal mortals is that she has the ability to see through the Mist, an ability thus far known only to be shared by Ariadne, Sally Jackson, May Castellan, and a few small children. (However when the children try to point out the strange things they see to their parents, their parents never listen to them.) Because of this, she can see through any non-mortal disguise and mist shrouded locations, such as the Labyrinth.

Physical description
Rachel wears over large shirts, doodles on them, and pokes holes in them when she is bored. She has frizzy red hair and green eyes, and is noticed as attractive by a seemingly jealous Annabeth. Rachel is also one of the few mortals that can see through the Mist, something that hides monsters from the eyes of humans, even though she's not a demigod. She becomes the Oracle of Delphi in the end of The Last Olympian and her Great Prophecy is:

Seven half-bloods shall answer the call, To storm or fire the world must fall, An oath to keep with final breath, And foes bear arms to the Doors of Death.

History
It is mentioned that Rachel's hamster had died and they called Dr. Arkwright when she was six. It is also infered that Rachel had a rocky relationship with her father, Mr. Dare, before Percy met her.

The Titans Curse
Percy first meets Rachel in The Titan's Curse at the Hoover Dam, where he mistakes the sound of her blowing her nose for a skeleton soldier speaking, and tries to run his sword through her. She sees that Riptide is a sword, and Percy is dumbfounded that a mortal is seeing through the Mist. Rachel then sees the skeleton soldiers, and tells Percy to hide. He runs into a bathroom, and she acts freaked out and tells the skeleton soldiers that 'some guy with a sword' ran in some other direction. They believe her, and Percy tells her to forget what happened. She tells him her name, and asks for his. His answer is 'Percy....gotta go!' Percy does not see Rachel again for some time, and he always assumed she lived in Hoover Dam.

The Battle of the Labyrinth
Percy runs into Rachel at the orientation of his new school, Goode High School. He tries not to run into her again, because that will cause awkward questions, but she instead finds him, and warns him about the two cheerleaders that have been following him.

They hide, and Percy tells Rachel that the Greek gods are real, and just about when he is going to tell her that he is a demigod, the cheerleaders find them and attack.

After a skirmish with the two Empousai there is an explosion, and Rachel rushes Percy out the back exit, and they run into Annabeth. Rachel tells Percy to run, and that she will make up some story. She writes her phone number on his hand with a permanent marker, telling him to call her, because he owes her an explanation, much to Annabeth's dismay.

Later, after wandering through the Labyrinth for a while, Percy goes to her for help in navigating Daedalus' Labyrinth in order to locate Daedalus. She sets off with Percy and Annabeth through the maze because they need her help. The demigods are worried someone will miss her, but she explains that no one would care if she were gone and leaves it at that. After finding that Daedalus has struck a bargain with Kronos, she escapes with Percy and Annabeth. Eventually the trio finds Kronos's headquarters. Kronos has, however, inhabited Luke and attempts to chase Percy down. Rachel appears with Annabeth and Nico and throws her hairbrush at Luke's face, which momentarily confuses Kronos. She also mysteriously manages to convince a limousine driver to ditch his client and take her and the others around to look for an entrance into the Labyrinth. She also assists in finding the lost god Pan and is present for his death. Later she parts ways with Percy, Annabeth, Nico, Grover, and Tyson, but not before revealing that her father is a wealthy businessman who buys up land and turns it into malls. Pan's death affects her, mainly because of her father's job. She expresses interest in hanging out with Percy again, much to Annabeth's dismay. Percy promises to call her and mentions that he has memorized her number, much to Rachel's delight. Later, during his birthday party, Percy laments not thinking of inviting her over, but was too afraid to try.

Rachel grows more and more fond of Percy throughout The Battle of the Labyrinth, just as Annabeth grows very jealous of her. Rachel sees that Percy and Annabeth seem to have a lot more feelings for each other then they will admit. She can also see that Annabeth is jealous of her hanging out with Percy and tries to give him the hint that Annabeth likes him, too, but Percy doesn't seem to get it and she calls him "blind" because he is a boy. It is, however, made clear that Percy does have some feelings towards Annabeth, and she does, too. Annabeth and Percy go out later in the fifth book.

The Last Olympian
Rachel and Percy are on the beach, driving Percy's stepdad's car around when Beckendorf comes on Blackjack, the pegasus, to take Percy away so they can bomb the Princess Andromeda with Greek fire. Before he leaves, Rachel kisses him on the cheek. She is hoping to beat Annabeth to the punch. Percy, however, quickly pulls away as he does not like her and from that moment onwards he resents her (it is unknown if he ever forgave her). Beckendorf makes a joke about not telling Annabeth about it, and Percy responds by saying, "Oh Gods, don't even think about mentioning it." Rachel later must go with her parents on a vacation, but she soon realizes something is wrong. She begins painting things she had never seen, such as Luke as a young boy. She also wrote Percy's name, Perseus, in Greek on the beach in the sand. She heads to New York to find out what is happening with Percy, and when the battle is over and she returns to Camp Half-Blood, she realizes that she can take in the spirit of the oracle, and become Priestess of Delphi. She was born with the gift, and with the curse of Hades lifted, successfully becomes the new oracle. She decides to still go to school but shortly before she leaves she recites a prophecy which is assumed to be the next great prophecy.

Powers/Abilities

 * Has the ability to see through the Mist to an extent where she can navigate through the Labyrinth and foresee its various traps
 * Can use the influence and wealth of her father to arrange services
 * Can see past and future events as well as make prophecies.

Film
Rachel has not yet been cast, and presumably will not be until the film version of The Titan's Curse starts production.