The Demon Linked with the Netherworld is the one hundred fifty-fourth episode of the InuYasha anime.
- Kikyō and Inuyasha reunite for the first time since Kikyō's supposed death and Mount Hakurei; they discuss Naraku's plans to find the last Shikon no Tama shard, and Kikyō gives Inuyasha a sacred arrow to give to Kagome so that she might use it in battle with Naraku, though, she says, only Kagome will be able to determine whether or not she can use it.
- Naraku betrays Princess Abi and Tekkei and slays them both, claiming to Inuyasha and his friends that the path to the Netherworld is now open.
Kikyō's helpers fly off after telling Inuyasha that Kikyō waits for him and wishes to see him. Inuyasha follows them into a forest, where he finds Kikyō who is resting with her soul collectors. Miroku sees him leave.
Kikyō and Inuyasha discuss Naraku's plans to get to the borderland between this world and the afterlife. Miroku soon tells Kagome that he saw Inuyasha leave with two young children and Kagome realizes he has gone to see Kikyō.
Meanwhile, Kikyō asks Inuyasha if he and his friends intend to go the borderland and Inuyasha states they are since the last sacred jewel shard is there. Kikyō then warns Inuyasha not to bring Kagome to the borderland, confusing Inuyasha. Kikyō tells him that Naraku removed the barrier around Princess Abi's nest for a reason; Naraku is after Kagome's eyes, her ability to see the jewel shards. Kikyō says that she is almost certain Naraku wants to lure Inuyasha and everyone to the border between the two worlds and then use Kagome to locate the last shard. Kikyō tries to leave to hunt down Naraku, but is clearly physically unable to. Inuyasha begs her to stay where she is and heal insisting she is too weak to do something so dangerous as Naraku wants her dead. Kikyō then gives Inuyasha an arrow which she tells him to give to Kagome saying only she will know when to use it.
The next day, Miroku, Sango, Shippō and Kagome continue to wait for Inuyasha. Inuyasha comes back and talks with Kagome. He then flat out says he went to see Kikyō and when Kagome asks, "What about it?" he then gives her the arrow that has been rubbed with dirt from Onigumo's cave saying Kikyō wanted him to give it to her. He then further tells her that it should work on Naraku. He asks if she is upset, to which Kagome replies "Not really. I trust you, Inuyasha." But then adds on that she wants him to honestly tell her what happened between him and Kikyo; causing him to realize she doesn't believe and is also angry.
Inuyasha and his companions race towards the demon bird nest, and Inuyasha picks up Naraku's scent near the nest. Inuyasha recalls Kikyō telling him that Naraku wants Kagome, needing her power to see the sacred jewel shards to locate the last remaining one. He then warns Kagome that she may "face more danger," even more than the rest of the group. He then vows to do whatever it took to protect her, silently refusing to let things go Naraku's ways, and Kagome says she knows he will.
Princess Abi's mother is healed, and comes out of her nest to meet Naraku. The two bird demons attack Naraku, and Princess Abi's mother consumes him.
As Inuyasha and the others approach, they see Princess Abi and her mother. They learn that Naraku was eaten, and the battle ensues. The battle is interrupted when Princess Abi's mother falls as Naraku breaks out of her head. Naraku slays Princess Abi as well then reveals that the passage to the borderland is open.