As the shuttle ascends into the atmosphere over Mortis, Anakin has a vision of himself on the planet surface. There, he encounters a likeness of himself embodied in the Son. The Son beckons Anakin to the dark side, asking him to join him so that they may change the balance of the universe. Anakin refuses. Enraged, the Son transforms into a gargoyle and lunges at Anakin, awakening him from his vision.

The Son appears within the shuttle and grabs Ahsoka. He drops through the floor into the clouds below, gripping Ahsoka as he transforms into a gargoyle. Anakin takes control of the shuttle and pursues the Son through a canyon, weaving around tall stone spires until he nearly hits the top of a large tower, suddenly revealed in the fog.

The near-miss disables the shuttle, and Anakin brings it down for a hard landing on the planet surface. Obi-Wan and Anakin escape unscathed, spying the tower in the distance. Anakin is determined to go after Ahsoka, while Obi-Wan feels they should consult the Father first. Anakin starts for the tower alone.

Ahsoka is imprisoned in a dungeon. A small creature appears and frees her of her bonds, but then bites her arm. As she loses consciousness, the creature reveals himself to be the Son, claiming she is now his. She lies unconscious with her body overcome by signs of the dark side.

At the monastery, the Father warns the Son not to give in to his vanity and the power of the dark side. He implores the son to be strong and resist temptation, threatening that if he cannot, the Father will be forced to contain him. With this threat, the Son unleashes a volley of red Force lightning at the Father, knocking him unconscious just as Obi-Wan enters the monastery.

The Father lies unconscious as the Daughter looks over him. Obi-Wan pleads for her to help Anakin stop the Son from leaving Mortis and wreaking havoc on the universe. She weighs the Jedi's words and tells him to follow her.

The Daughter leads Obi-Wan into a large chasm wherein lies the Altar of Mortis. At the altar, Obi-Wan draws out the Dagger of Mortis -- a blade, the Daughter explains, that will give its wielder the power to control her brother.

Anakin climbs into the tower and finds Ahsoka waiting. Anakin urges her to leave with him, but she turns on him instead -- he will join the Son in the dark side or be forced to kill his own apprentice. Ahsoka bounds toward Anakin with her lightsaber, forcing Anakin to take a defensive position. He deflects her blows but does not attack.

The Daughter and Obi-Wan confront the Brother, who admits he tried to kill his Father. When the Son hints that Anakin is in trouble, Obi-Wan races from the chamber to find him.

Anakin is joined by Obi-Wan in fending off Ahsoka's attack. The Daughter tries to follow to help, but her brother holds her back. She will be forced to fight him. The two appear equally matched, with the Son's attacks either deflected or turned against him by the Daughter. The Father, awakened by their conflict, arrives to intervene. He hurls them both through a window and into the middle of the dueling Jedi.

The Son attacks the Father with a sustained volley of Force lightning, the intensity of which is too much for the Father to deflect. As Obi-Wan tosses the Dagger to Anakin, Ahsoka intercepts it and gives it to the Son. With her usefulness at an end, the Son kills Ahsoka.

As Anakin lunges toward the Son, the Force-wielder effortlessly casts the Jedi off. The Son, with Dagger in hand, now moves to kill the Father. He is interrupted by the Daughter, however, who moves between them and receives the death blow instead. The unexpected action appears to both enrage and anguish the Son, who transforms into a gargoyle and bounds into the night sky.

The Father too is anguished, fearing the loss of his Daughter -- and the balance of the Force -- is now certain. In a final selfless act, the Daughter transfers her remaining life force through Anakin to save Ahsoka. His apprentice awakens, free of the Sith spell that consumed her.

The Father warns that the Sith will be strengthened by his Daughter's death, and that the Jedi must leave Mortis before the Son can take their ship.