You are Ember Edwards, the least popular girl in school, but everything changes when you find a doorway to another world.
Ember Edwards is the most unpopular girl in school. Her parents are irresponsible slobs who rarely care about her, and she is constantly made fun of at school. She lives a mostly lonely life and secretly dislikes the harsh way everyone treats her.
Things get their worst for Ember when she is asked out by two boys to the prom, and believes she actually has attention. On the day of the dance, the most popular girl, Alice, reveals that it was all a trick - the boys had to embarrass themselves with Ember to get a kiss from her, which she doesn't give. Both sad and angry, Ember runs off to an abandoned room and enters a "universe splitter" room with two doors. The one she chooses leads her to a new world.
Upon arriving, Ember meets two boys, Kellan and Ash, who help her learn more about the world she fell into, called Eterna. In this world she's the most feared human, as people think she is out to destroy them. During their search for the truth they find that Eterna is created by people from Britain who wanted a world free from Earthly discord. Ember also learns, later, that the ruler Lady Astaria is actually her older alter ego who was split from her when she entered the universe splitter room. While the Player Ember entered the first door, Eterna in the present day, her other half went through the second door to Eterna fifty years earlier. She is the angry, rebellious side of Ember while the Player's version is the weaker, more forgiving one. In a confrontation with Astaria, the Player's Ember convinces her to abandon her anger. Ember nearly dies at Astaria's hands but is saved by Kellan and Ash.
Kellan and Ash continue to take care of Ember as the Consuls, Astaria's employees, pursue her. Astaria has stepped down and the Consuls are furious at losing their jobs. In the meantime Ember grows closer to Ash, and Kellan's actions become more suspicious with his jealousy. He not only tortures a consul to death but also kills Ash's parents to make him suffer.
Ember and Ash try to escape Kellan's clutches, and end up in Earth again through the universe splitter door. At one point Ember and Astaria are both found and determined to be identical people with different ages, which the press finds to be due to the universe splitter room and dubs "The Ember Effect." But they cannot exist together in one universe, and Lady Astaria soon fades away. A little triumph occurs for Ember, when Ash takes her to prom and shocks everyone, including Alice, whom he rejects for Ember.
Kellan, who followed Ash and Ember into Earth, continues to pursue Ember and tries to kill her multiple times. He sends Ash back to Eterna, and Ember must try to reach him while people on Earth demand to dismantle the Eterna machinery, threatening the existence of the entire world. After finding the machinery in a government building, Ember runs into Kellan and the Player can choose to shoot him. Without Kellan in the way, Ember tries to enter the right world but fails on her own. She ends up in the world of Phoenix Faraday, from The Phoenix Prophecy. Phoenix points her to the wavecrusher machine, which takes her back to Eterna, and she saves Ash from being stuck between worlds.
In Eterna, Ember and Ash resume their relationship and decide to get married, not knowing how long Eterna will last in the hands of Earth's people but wanting to make the most of their time together. Back on Earth, it is revealed that a government employee ordered to dismantle Eterna decided to keep a piece of it intact. This piece happens to be a glowing green cube which he suspects is the key to Eterna's continued existence. Little does he know that, as he wishes Ember a happy ending in Eterna, it is already truly happening for her.
Ember Edwards - The main protagonist in the story, a young girl accustomed to being rejected by everyone around her. She stumbles upon a universe splitter room which takes her to Eterna.
Ashton Cross - A boy who helps Ember through Eterna. He becomes her boyfriend and later husband.
Kellan Keystone - Another boy who helps Ember in Eterna. He is initially kind to Ember, but turns out to be a psychopath. In the latter part of the story he tries to kill Ember multiple times.
Lady Astaria - Ember's alter ego, her angrier self who went through the second door to Eterna and is fifty years older than her.
Ember's Parents - Two irresponsible adults who act like drunken, slobbery children and are not fit for taking care of her. Surprisingly, they have not yet been found out by the government.
Alice - The most popular girl in school, who plays a cruel trick on Ember for prom.
Ivy - Alice's friend, who participates in the prank on Ember.
Grand Consul Raven - Lady Astaria's right-hand man, who spares Ember because he was in love with Astaria when he first met her, and Ember is the exact copy of her younger self.
Ashton's Parents - Two very loving adults in which the mom immediately offers to be the motherly figure Ember's never had after discovering from her son the horrible home life she has had. However, they are later killed by Kellan.
Phoenix Faraday - From The Phoenix Prophecy, a girl who helps Ember return to Eterna and find Ash again.