The young Bronze Saints are taken by Bear Geki to the Hell Camp, which is full of lethal traps composed of the elements of Cosmo. Those who survive the Camp are elligible to become Silver Saints. Kōga and Sōma must work together to overcome the obstacles, all while Sōma must avoid fellow Saint Argo's hostility and haunting memories of his past.

The Saint Fights tournament continues. Geki and Kōga bond more while the former teaches the young Saint about the mysteries of Cosmo, and reminisces about his defeat at the hands of Seiya years ago. In the tournament, Yuna triumphs over Delphinus Güney, and Kōga and Sōma are pitted against each other in battle. As both are driven by strong motivations, Kōga draws more strength from the memories of Geki to narrowly achieve victory over his friend.

Kōga and his friends continue their trek escorting Aria, until they come to a enormous whirlwind blocking their way. Meanwhile, Mars reveals his plans for his Tower that he deems the new Twelve Zodiac Temples, to his daughter and son, Sonia and Eden. A moribund Athena is also revealed by Mars, held hostage inside his tower. The young Saints decide to brave the whirlwind, managing to find a way inside it with the help of Yuna's command over wind. The traitorous Musca Fly tries to steal Kōga and Yuna's Cloths, only to be defeated in a fierce battle. Weary and alone, the young Saints find a new light of hope in the Pegasus constellation, which reveals a message from the legendary Seiya: "To you, I entrust Athena!"

The episode begins with our heroes walking through the woods as we find they are looking for the Earth Cosmo Core. Haruto appears, informing them that there is a town in front of them and a visitor behind them before he disappears once more, despite them asking him to stay. The "visitor" turns out to be Ichi, the older Saint from Palestra that was never able to use his powers correctly, and since that time the bronze saints found some surprises along the way.

Eden takes Aria away, and Aquila Yuna and Pegasus Kōga resume their journey, demoralized by their failure to protect their friend. Along the way, Yuna and Kōga separate, meanwhile Eden and Aria reminisce about the happy days they shared during their childhood. Kōga later meets a young man who first mocks his weakness, luring the teen Saint into a fight. Kōga later realizes the man to be the owner of an immense Cosmo, and turns out to be Cygnus Hyōga, one of the legendary Saints who protected Earth from great menaces many years ago. Hyōga manages to teach Kōga that to reach the true potential of his Cosmo, he must first believe in himself. After learning Hyōga's lesson, Kōga rejoins Yuna and both resume their way with renewed resolve.

The young Bronze Saints decide to invade Mars' stronghold to rescue Aria. The teenagers carry out their plan, finding strong opposition in the enemy lines. During a moment of desperate need, the Bronze Saints receive the assistance of Lionet Sōma, who rejoins them, stronger than before, thanks to further training under Unicorn Jabu, the Bronze Saint. The Saints reach Aria's chambers, only to find she has left. Not all is lost, as Sōma is able to retrieve the Southern Cross Cloth's Clothstone, which belonged to his father Kazuma, after defeating Hornet Sonia, his killer.

Souma and Sonia are entrapped in an illusion of their past when Souma's father Southern Cross Kazuma was alive. Sonia is revealed to have been ordered by Medea to kill the Silver Saint for he was an open leader against the Martians. Hesitant on her mission she departs and faces Kazuma, as Souma also witnesses the past event. Sonia is first easily pushed away by Kazuma who tells her that her fists are made to protect those she care for, but when she thinks of her family, Sonia bursts into a rage and stabs Kazuma from the back. It is revealed then that after the murder,...

After the defeat of Kouga at the hands of Harbinger, the remaining Bronze Saints engage him in battle, meeting with utter defeat. Harbinger reminisces about his difficult childhood and what drove him to a life of violence, to become the strongest and eventually a Gold Saint. Managing to recover after witnessing the defeat of his comrades, Kouga attacks Harbinger with a single blow imbued with all the power of his Cosmo. Much to his surprise, Harbinger emerges unscathed and his comrades have vanished.

After Cancer Schiller's defeat, the Bronze Saints prepare to proceed further into Sanctuary. Meanwhile, Orion Eden reminisces about his late friend Aria. The grief-stricken Bronze Saint begins to question Mars' motives and their legitimacy, going as far as to challenge his master Leo Mycenae because of his loyalty to Mars. Mycenae and Eden engage in unequal combat to prove their conviction.

Souma and Sonia, who has been given the Scorpio Gold Cloth by Medea, engage in their long awaited final battle at the Scorpio Temple.