The oafish demon Gouki is using the stolen Orb of Baast to capture children's souls. If Yusuke doesn't track down and defeat this monster quickly, those souls will become the monster's next meal. But Gouki isn't the only one Yusuke has to worry about when the second thief suddenly appears. His name is Kurama, and to great surprise, he asks Yusuke for a favor...

Yusuke returns from training with the great psychic Genkai, and not a moment too soon! Dreadful Makai Insects are invading his own city, part of a sinister scheme to flood the earth with demons! With Kuwabara at his side, Yusuke dives into a forbidden demon city. His target: four deadly creatures known as the Saint Beasts!

Yusuke, Kuwabara, Kurama and Hiei rush into the next part of the castle as they reach the final chamber where Suzaku awaits. Unknown to them Suzaku's master plan is being made - to capture Keiko.

One giant battle stands in the way of rescuing Yukina. Yusuke and Kuwabara versus the leaders of the demon mercenaries, the immensely powerful and bizarre - Toguro Brothers! What will it take to defeat the freakish duo in a fight where anything goes? Elsewhere, Kurama races to stop Hiei, who is entering Tarukane's stronghold with his own violent agenda!

Yusuke jumps out of his slumber, ready for the final fight against a new fighter named Chu. He’s rude, he’s crude -and he claims to be Team Rokuyukai’s true leader.

Round two of the tournament arrives and Team Urameshi must face Dr. Ichigaki’s fighters, a group with a habit of chopping off their opponent’s heads! Will Yusuke be the doctor’s next guinea pig?

Okay, brief recap to what happened last episode: Kurama has just had his arms and legs frozen, but used his spirit energy through his hair when he used the rose whip to slice Gama apart. And like in the last episode, Gama tries to hit Kurama through his wounds, splattering his blood all over him. Right before he dies, Gama tells Kurama that his blood has sealed his spirit energy. Uh-oh. To make matters worse, the next member, Touya is ready to fight and avenge his dead teammate. Touya attacks just as Gama's first spell wears off, allowing him to move, but with his energy still sealed, he's still in a bad situation. Kurama spends all of the time trying to keep himself from getting killed by Touya's attacks. Eventually, he forms a plan to defeat Touya, and gets himself cut on purpose to plant one of his death plant seeds inside his own body right so it can manifest as a weapon.

This episode starts with Jin in the air with his Double Tornado Fist ready for the kill. All of a sudden Yusuke says, ""Time for something stupid."" His body becomes surrounded with spirit energy. Everyone is surprised-Botan, Kuwabara, Kayko, Koenma. Then Jin attacks with the first tornado fist. Yusuke somehow catches the fist. Jin exclaims, ""No one can catch a tornado!"" Yusuke throws the fist, rendering it useless. When Jin attacks with the second fist, Yusuke catches it with his foot. He also makes the Tornado Fist useless. He yells, ""SPIRIT WAVE"" and a punch full of blue energy nails Jin right in the stomach. Jin goes flying in the air. The Masked Fighter explains that the Spirit Wave is like Yusuke's shotgun attack and that he must have learned it from Genkai. In the stands, Kayko is shocked, but Shizuru says, ""Let's move."" All of a sudden, a sparkle is seen in the sky and Jin's body comes crashing down in the stands. Koto makes a ten count, and Yusuke is the winner.

Genkai tells Yusuke his final test is to kill her. Yusuke has second thoughts. He meets Genkai in a cave and says he can't do it. She tells him that was the first part of the test. She would not give her power to someone who would kill her. She reveals her source of power is her Spirit Wave Orb. She takes out a bright ball of energy. Yusuke's test is to absorb it. He agrees to the terms, though the test could kill him. She puts it in him. He feels nothing at first, but then he collapses and pain. In a new ring, the semifinals begin. Team Urameshi enters, missing two of their members (Genkai and Yusuke). They are facing Team Uraotogi. Hiei and Shishiwakamaru agree to choose the fight by dice. The first fight is Hiei vs Makintaro. Hiei wips out his katana. Makintaro asks him to make a move. Hiei holds up Makintaro severed arm. Makintaro reveals his attack, the Axe-blade fist. Hiei is too quick for him and stabs his head. Meanwhile, Genkai watches Yusuke suffer through her test.

The match between Shishiwakamaru and Genkai begins. Genkai is very weak because she has given Yusuke her Spirit Wave power through the Spirit Wave Orb. Genkai however, has a great deal more wit than Shishi, and really nails him a few times. Shishi then decides to use his second item: the Banshee Shriek. Shishi is really excited beacause he thinks by using his sword to defeat Genkai, he'll become famous. He then shows off his power of the Chorus of a Thousand Skulls on the audience, killing many. Genkai is able to dodge it. After one more chorus, Shishi uses another of his new sword's power, the Death Cage. Genkai and Shishi are surrounded by a barrier of energy. Shishi goes in for the kill with an attack in which he puts his spirit energy into his sword when Genkai catches it and fires the Spirit Reflection Blast, blasting Shishi right through the cage.

The members of Team Toguro demonstrate their power in the semifinals by utterly defeating another team with minimal effort.

The tournament finals are set to begin. But the rules state that each team must have five members to compete. With each team having only four fighters, two competitors step up to join with each team no matter what the consequences. Who are the two new fighters and what could they possibly bring to the team?

Hiei unleashes his most powerful attack, the Dragon of the Darkness Flame! But Bui is able to turn the Dragon against his master. Will Hiei be swallowed and destroyed by his own power?

Yusuke reveals to Toguro that he has not been fighting at full power and removes the Spirit Cuffs, which reduce his power. Finally, a fully powered Yusuke launches an attack at his nemesis. But Toguro too has powered up to his top level and stares down Yusuke's most powerful Spirit Blast.

As one of his friends lies on the arena floor, Yusuke powers up to the same level as Toguro. To defend himself, Toguro must power up to 120% of his capacity. Can either fighter, each completely devoid of any remaining energy, survive to claim the prize?

Team Urameshi prepares to depart Hanging Neck Island the victor of the sinister Dark Tournament to return to the world of the living leaving their fallen mentor and friend behind. But somewhere far away a chance encounter between two former allies seems to hint at what is to come as the most unlikely of people reveals a most shocking secret.

Searching Mushiyori City, Yusuke's team was quickly steered to the hospital, where a trap awaited. There they encounter the Doctor, a human with immense psychic powers, super strength, feels no pain, and has infected the entire hospital with a deadly virus. To save his friends, will Yusuke be forced to destroy the wretched creature?

Sensui makes his appearance, and battles Yusuke, Kuwabara, and Kurama. Sensui's abilities enable him to battle all three on equal footing. During the battle, Sensui manages to kidnap Kuwabara.

Kurama's anger has sentenced Toguro to an eternity of suffering, forever chasing his foiled revenge. But the tunnel to Demon World is opening. Can Yusuke's team still save the human race? Only a dramatic showdown between the past and present Spirit Detectives will reveal the truth!

Yusuke comes to terms with the fact that he cannot defeat Sensui. Watching but unable to help, Kuwabara fights off emotion with rage as he remembers all the good times and bad he's had with his best friend. Kuwabara manages to free Kurama and Hiei, but it's too late. Yusuke Urameshi has been destroyed.

Yusuke and team return topside to the waiting arms of their friends. But all is not well. King Yama's soldiers arrive saying that they must destroy Yusuke once and for all. Could this be the end? How much energy does the Spirit Detective have after his exhausting battle with Sensui?