The Death Door is the sixth episode of Season 1 and sixth overall for the TV show 101 Crosses. Two twins, one who controls shadows and one who controls light begin attending Cross Academy and the secret passage created by a rogue Cross 50 years ago is opened and Crosses start dropping like flies. The reception for the episode was (placeholder). This episode was 1 hour, rather than the usual 30 minutes.
The door to Cross Academy opens wide as the Headmistress Sofósi walks out, with two Crosses following. The bubbly blonde teen known as Draco and the quiet shy brown haired teen Tsuki enter, with Sofósi introducing the students of Cross Academy to them. Draco has control over light, and Tsuki has control of darkness. X seems interested in Tsuki, guessing that the quiet boy has a taste for mischief as he does. Jenna fawns over Draco though, much to X's dismay. Tsuki is relatively ignored among the students, and X is the only one who greets him. X comes up with a plan to Draco, making Tsuki grin.
Tsuki and X explore the academy by night hoping to trick him into thinking that he is seeing a ghost. They sneak around but he is no-where to be found. They think they hear someone, and pop out from a corner, but to their horror see a young girl dead on the floor with massive stab wounds. Engraved into the wall is the word "JUSTICE". They head to Sofósi immediately and show her the situation, scaring her. She thanks the boys for their help and calls for the other teachers to clean up the body and tell her parents.
The next day Sofósi informs the people about the death of the young girl, causing paranoia and fear. X tells Jenna about what he saw, and Jenna concludes that Tsuki was the murderer, due to his silence and un-nerving attitude. She also wonders how he could have gone down that path without knowing that she was dead, and theorizes that he isolated X to kill him as well. X fiercly disagrees, but Jenna is too busy talking to Draco, who is as popular as ever. Draco expresses sadness at her death, causing a horde of girls to come and comfort him. X rolls his eyes and sits with Tsuki who is being bullied. X knows that Tsuki is innocent and promises to find the real culprit and clear Tsuki's name.
X scouts the school grounds and discovers nothing, getting frusterated. He wonders how the killer could have done it considering the massive wounds, and how they are traveling the grounds without being caught. He becomes sloppy and loud and finds the staff that night looking at the dead body of a young boy, with blood on the walls spelling "SINNER". Eugene theorizes that the infamous Death Door has been opened, bringing shock to the other teachers. X hurries off to his room and wonders what the Death Door is.
The next morning X asks Jenna what the Death Door is, confused. She states that not many know of the secret chamber, but that a good deal of time ago it was created by a rogue Cross who murdered fellow students, and used it as a hideout and place to store his secret weapon he used to kill the students. X tells Jenna that he overheard that the staff thinks that the door might have been opened. Jenna is shocked, but does not outrule the possibility. X now has a goal, find the Death Door.
X takes up the hardest task yet, reading more about the Death Door. In the Library he discovers a book about the Death Door entitled "The Legend of the Death Door", causing the library to faint due to X never reading. He learns that in the year 1946, a deeply disturbed Cross orphan named Etodor Erup was attending the school and was frequently bullied. Etodor was silent and seemed relatively un-affected, acing all of his classes and learning as much as possible. However, he was really learning about the philosophy of an infamous regular human in medieval times who believed God would send a messiah to kill the Crosses and silence their imperfections, and called for them to "realize" and absolve their sins by killing themselves and other Crosses. Etodor soon became obsessed with the philosophy and created a mechanical monster to utilize in killing the Crosses, and sealed it in a secret passage he created. The passage became known as the Death Door, and he slaughtered many innocent Crosses until he was caught and commited suicide.
Although this spreads more light on the killer's motives, he still does not know how to find the Death Door and brings the book to Jenna, hoping she can help. In a few seconds she quickly points out multiple possibilities, but guesses the fountain on the third floor, due to it's god-like appearance and the fact that there are no classes on the floor, just storage. She then discourages him from looking for it considering the danger, but he is already gone, and Jenna knows that there is nothing she can do to change his mind.
He goes to the fountain and blasts a sphere of ice at it, but to no avail. He then punches the fountain in anger, and a stone from the fountain that was protruding now goes inward. He realizes that the stone has the letter E on it, and punches the stones with the letters R, U, and P. The fountain spirals around in a circle going into the ground, and the fountain dries up, revealing an entrance. He begins climbing down, but a blast of energy knocks down the ladder and knocks him to the floor. X writhes in pain and hears a familiar voice comforting him in a patronizing voice. He recognizes the voice as Draco.
X listens to Draco's explanation as things begin to fall into place. Draco's fake kind and caring and sensitive behavior made him well-liked and created a group who could viciously defend him if any accusations were had, his great grades and history made him able to move around un-noticed, his brother's dark powers and attitude would take the attention away from him, and his knowledge allowed him to find the Death Door. X asks how Draco, with his light powers, could do this. Draco explains that he is light, he is pure, and he is bringing justice in his mind. He tells that he will obliterate the Crosses and then kill himself, cleaning him of sin and bringing pureness and perfection to the world. He soon brings out the mechanical monster created by Erup, a gigantic robotic spider with blades for legs, explaining the stab wounds.
Draco mounts the beast and combat begins. X blasts ice at the Spider but it's warm fur melt it, rendering X useless. It knocks X down and slashes his chest. X writhes in pain and X pins him to the ground, preparing to kill him. While the Spider is up, a break in it's fur revealing it's gears is revealed. X shoots ice at it freezing up the gears and breaking the spider in an explosion, knocking Draco to the ground. X gets up and the two do battle. However, X notices that Draco's light is becoming weaker and darker due to his vile deeds, and X is able to knock Draco down. Draco gets up and reveals a tool Erup planned to use before his death, a work in progress sword known as the Darkslayer, infused with light power. Draco slashes X once more and X can't last much longer. He prepares to bond his light witht the sword to cleanse X once and for all. However, Draco's bad deeds have snuffed out his light and turned it into darkness. The darkness and light cannot handle each other, and the blade explodes, blasting it's sharp edge into Draco's heart, killing him in a splash of blood.
Jenna then comes and helps X up and she sees Draco. X tells her that he was the killer the whole time, and rubs it in her face. They bring the staff and X is congratulated and awarded for his help in stopping Draco before more Crosses were killed. X himself tells Tsuki. Despite their differences Tsuki is saddened, but thanks X for stopping Draco and bringing justice. The entire school mourns the two Crosses who are dead, having learned a valuable lesson the hard way, don't judge a book by it's cover.