The Mysterious Light that Guides the Saint is the one hundred fiftieth episode of the InuYasha anime.
- Saint Hijiri protects a group of humans from Princess Abi and her demon birds, leading Abi to bemoan her new alliance with Naraku, saying that ever since they joined forces she has faced more interference than ever.
- Inuyasha and his friends arrive at the scene just after Hijiri left; Inuyasha decides that they must search for this Hijiri, much to Kagome's disappointment, as Hijiri might turn out to be Kikyō.
- As Inuyasha, Miroku and Sango deal with Naraku's demons, who are also searching for Saint Hirji, Kagome goes on ahead; she enters through a barrier where she sees Shinidamachū and eventually finds Kikyō at the base of a waterfall, in the water below.
Inuyasha, Kagome, Sango and Miroku look at the arrow that broke Hakudōshi's barrier. They all wonder if it was shot by Kikyō, but Inuyasha tells them that it does not have Kikyō's scent on it. The villagers with them suggest that the Holy One they seek may have shot the arrow.
Near the village of the Holy One, Princess Abi and her demon birds are attacking the villagers who are protected in a cave by a barrier. As the villagers are beginning to flee the barrier in panic, the Holy One arrives and quickly slays all the demon birds with a single arrow. Surprised by her defeat, Princess Abi flees.
Inuyasha and companions arrive just after the Holy One has left to pursue Princess Abi. They consider whether they should follow the Holy One.
Kagura watches as Hakudōshi heals himself with his barrier, and she realizes that his heart is not held within his body.
Inuyasha and his friends follow the Holy One's path to the Forbidden Mountain, and along the way they see a lot of demons also seeking the elusive saint.
Inuyasha sends the rest on while he stops to battle the demons behind them. When he finishes, he runs into the Holy One and her helpers, and demands to know who she is.
As the others stop to battle demons, Kagome sees a pair of soul collectors and pursues them.
Inuyasha approaches the Holy One, only to find that it is a puppet. When it disperses, Kagura is overhead. She tells Inuyasha that Naraku thinks Kikyō is still alive, and that the arrow that broke Hakudōshi's barrier was smeared with dirt from Onigumo's cave.
Kagome runs through the forest, chasing the soul collectors. They lead her to the base of a waterfall. When Kagome looks in the water, she sees Kikyō.