Episode 18

Tell Me The Secrets of This World is the 18th episode of the Gurren Lagann anime. It first aired on July 29th 2007.

Synopsis
As Nia finishes making her speech about the Humanity Eradication System, Rossiu is trying to have his men locate the source of her transmission, but it soon ends. Kittan and the others are then tasked by Rossiu with fielding the flood of phone calls coming in from citizens uneasy about the declaration of war. As for Rossiu himself, he has gone to the biocomputer and watches as it is activated. After getting his men to leave the room, Rossiu tells Lord Genome to wake up so that he can explain the mysteries of this world. Simon meanwhile heads for Nia’s home, but she’s not there, and he can’t reach her by phone either. Gimmy and Darry then find Simon and pass along the order that the Gurren Lagann is to return to base, but Simon refuses because he’s still looking for Nia. He then tries to order them to get out of the way, but Gimmy informs him that Rossiu has authority over Gunmen sorties. Since Simon doesn’t show any signs of giving in, Darry tells him that because the Gurren Lagann is a symbol of their having recaptured the planet’s surface and a symbol of power, he can’t fly around in it without people being worried about there being another big battle. Seeing the truth in her words, Simon decides to let them have the Gurren, but he’ll be taking the Lagann to look for Nia.

The first place Simon checks is Reite and Makken’s repair shop, but Nia’s not there. Noticing how uneasy the two’s kids look after having seen Nia’s broadcast, Simon optimistically urges them not to worry and not to be afraid about the Humanity Eradication System. However, after Simon takes off again in the Lagann, Reite comments on how the one they’re worried about is actually him. With still no clue about where Nia is, Simon then sets down by a waterway and wonders if that was really her earlier. To his surprise, Nia suddenly appears beside him and tells him that she now understands that they’re incompatible. She then explains that the Spiral Nemesis brings about destruction to the universe, and that they, the Anti-Spirals, exist to prevent it. The Core Drill Simon carries is a symbol of the Spiral Nemesis, and they believe that the spiral power will destroy the universe. Back at the biocomputer, Rossiu is telling the reanimated head of Lord Genome that his memory and knowledge had remained as data. Lord Genome had died without telling them anything, and Rossiu now wants to know about the spiral power and the Anti-Spirals.

In response, the biocomputer reveals that the spiral power is the power to evolve. Life with spiral genes and the galaxy with a spiral structure all increase infinitely with the spiral energy - this is the law of the universe. However, then the Anti-Spirals who feared this power appeared. The original Lord Genome had protected this galaxy as a spiral warrior, and the Lazengann, Teppelin, and the Gunmen were all originally weapons used for fighting against the Anti-Spirals. The Lagann was one of their strongest weapons, a core machine that could control others by combining, and they had sealed it underground. What Rossiu doesn't understand is why Lord Genome oppressed other humans and forced them underground if he was a spiral warrior, so Lord Genome goes on to explain that they were defeated and returned to each of their home planets, which earth was one of. With control of the galaxy, the Anti-Spirals deployed Spiral Life-form Extermination Systems on planets with spiral life that would activate when the number of spiral life-forms on the planet exceeded a fixed number. Thus, Lord Genome had allowed a limited number of humans to live underground, but he did it by force because he knew that life driven by spiral instinct would blindly aim for the heavens. Words and reasoning could not suppress this urge, so the only thing that worked was fear.

Continuing a similar explanation to Simon, Nia asks if he had thought that the speed human civilization had advanced in the past seven years was strange. She claims that this is the potential of spiral beings and that population and civilization are evolving at an explosive rate. Because the spiral beings could become a power that threatens them, the Anti-Spirals want to destroy them before that happens. Despite all this, Simon remains convinced that they can win and urges Nia to wake up, but she replies that it’s impossible because she’s the Anti-Spiral messenger. As for the extermination of humanity, both Nia and the biocomputer say that in three weeks, the moon will leave its orbit and crash into the earth, which will be the end. Rossiu realizes that if the citizens found out, it would cause a huge panic, so he instructs Lord Genome not to tell anyone else about this. However, he then gets interrupted by Kittan and Dayakka who alert him to the fact that their moon probe was destroyed and to how Nia has been broadcasting everything she had told Simon. As she explains that she had the Anti-Spiral genes that activated and that once she becomes an Anti-Spiral, she won’t be able to turn back into a human, Nia’s body becomes covered in a dark coating.

Two more Anti-Spiral ships suddenly appear from a portal in the sky that Nia then disappears into. In response, the Grapal forces are scrambled to meet this threat which has been assigned the Mugan codename. Simon also recombines the Lagann with the Gurren and rushes toward battle, despite Gimmy and Darry’s warnings. Back at the command center, Leeron explains to the others that these Mugan have an energy field that nullifies attacks. To make matters worse, its entire body is like an explosive, so when the shields get taken out and the Mugan stops functioning, its body instantly becomes energy. It is under these circumstances that Simon now battles the two Mugan, though when he destroys one, he orders Gimmy and Darry to shoot the explosive pieces. Simon then takes out the other Mugan, and he joins the two pilots in blowing up the falling pieces. They ultimately succeed, but both Leeron and Rossiu recognize that this strategy won’t work with a larger number of enemies. Rossiu also realizes that this will have an adverse effect, and Simon sees this first-hand in the form of the thousands of angry protesters now gathered in front of the government building.

Rossiu heads out with a group of armed soldiers to get the crowd to calm down, but when the people see the rifles that the soldiers are carrying, they panic, and one of them throws a rock at Rossiu’s head. The soldiers immediately raise their rifles, but Rossiu stops them from firing and heads back into the building. Knowing that an uproar like this will spread in no time, Rossiu decides that someone has to take responsibility for what happened. Simon is staring at the moon thinking about Nia and the Anti-Spirals when Rossiu and his troops arrive to arrest him.

Major events

 * Nia is transformed into the Anti-Spiral's messenger.