"The Balance" is the eighteenth episode of Justice League Unlimited. It originally aired on May 28, 2005. Wonder Woman and Hawkgirl must put aside their feud and go to the depths of Tartarus when the evil sorcerer Felix Faust establishes dominion over Hades.
In her workshop, Tala is attempting to magically remove the Annihilator's weakness – to wit, its tendency to shut down in the absence of aggression. Her mentor, Felix Faust, now existing only as a disembodied spirit trapped in a mirror since she rescued him from Tartarus, is looking over her shoulder. When her latest attempt fails, he says he knows the answer, and tricks her into casting a spell that frees Faust and traps her in his stead. His spirit takes control of the Annihilator, and goes stomping out of Cadmus.
Aboard the Watchtower, Flash is trying to mend fences between Wonder Woman and Shayera, but failing miserably. As Diana passes the infirmary, she is surprised to see Etrigan, Doctor Fate, and Zatanna, all writhing under some invisible torture.
Wonder Woman returns to her quarters and finds Hermes, messenger of the gods, with a message that she has to return to Themyscira. Faust has entered the gates of Tartarus and usurped Hades's throne, in revenge for his betrayal. As a result, the balance between Olympus and Tartarus has been upset – hence the turmoil felt by the League's magic-users. By order of Zeus, Diana must restore it.
After an examination of her own weapons, Diana concludes that she needs Shayera's Nth metal mace, which disrupts magic.  She sneaks into Shayera's quarters to steal it, but Shayera catches her. Swallowing her pride, Diana asks to borrow it, but Shayera insists on coming with her.
Together they reach Themyscira, where Hippolyta objects to Diana breaking her exile. Diana says she must enter the gates. Before she goes, Hippolyta touches Diana's armor, unlocking its full power.
Inside Tartarus, the two women capture a demon, Abnegazar, who leads them, under the influence of Diana's Golden Lasso, to Hades's library, where Faust is happily immersed in tomes of ancient, forbidden knowledge. When they confront him, he sends them plummeting down a hole in the floor with a casual spell. In a snowy region of Tartarus, they find Hades, chained to a rock and being tormented by vultures.
They free him and the three of them return to the library to attack. In the ensuing battle, the library is largely destroyed, but Shayera's mace proves to be capable of hurting the Annihilator. Faust seizes Shayera and begins crushing her to death, but Diana takes up the mace and strikes a devastating blow. The armor is destroyed, and a tiny portion of Faust's sole is left drifting. Hades picks it up and announces he plans to make it his "hobby." He bids the ladies farewell, calling Diana "my child." When she objects, Hades claims that he and Hippolyta worked together in sculpting her from clay. Shayera assures Diana that Hades is lying, and she can ask her mother. Diana says she doesn't need to – she knows who her real family is.
Returning to Themyscira, they are welcomed by a cheering crowd. Despite the law of the gods, Hippolyta rescinds Diana's exile at last.
As they are welcomed to a farewell banquet, Diana and Shayera make peace – they may not be friends, but they are both content with being teammates.
- Diana's long exile, since the events of Justice League, "Paradise Lost," is finally ended.
- Felix Faust likewise refers to his betrayal and apparent death by Hades in "Paradise Lost."
- Hades may be lying; in "Paradise Lost," when he first saw Diana, he claimed not to have known that Hippolyta had a daughter.
- Tala does not reappear until "Dead Reckoning," when she has somehow been released from the mirror.
- Diana's enmity toward Shayera stems from the events of "Starcrossed."
- Last appearances of: Felix Faust, Hades, and Hippolyta.
- Bob Joles replaces John Rhys-Davies as the voice of Hades.
- Zatanna's voice actress for her brief mumblings is not credited; a likely candidate is Juliet Landau.
- Though the episode picks up on the events of "Task Force X," - specifically, the theft of the Annihilator from the Watchtower — it is technically not part of the Cadmus story arc.
- Hades's torture is reminiscent to that of Prometheus, who stole fire from the gods to give to men, and was punished by being chained to a rock and having his liver torn out every day (because it always grew back) by vultures.
- Wonder Woman's League identification code is 003; this implies that the expanded League now has upwards of 100 members, and also that the original seven founders have the lowest numbers (likewise, in "Hereafter, Part II," Superman's code is revealed to be 002, in "Flashpoint" J'onn's is 004, and in "Flash and Substance" Flash's is 006). It may also be a tribute to the fact that, in most comics portrayals of the Justice League, the three "leaders" are traditionally Superman, Wonder Woman, and Batman (as is also shown in the series' title sequence).
- The Atom
- Dr. Light
- Shining Knight
- Dr. Fate
- Booster Gold
Tala: And I'm supposed to take advice from you, when without my spell, your spirit would have been — poof! — lost on the winds.
Tala: This is really bad, isn't it?
Flash: You guys aren't even trying. You could at least talk to each other.
Hermes: I've got something for you, here, it's pretty important. Zeus paid for overnight service. Here it is.
Wonder Woman: Why should I care about this?
Shayera Hol: We become pals while I wasn't looking?
Shayera: That's right. I'm an angel. You can mess with me if you want to, but I don't think you wanna mess with the boss! (points skyward)
Shayera: Where's Faust?
Wonder Woman: Come on. We're putting you back on the throne.
Wonder Woman: What about us? Are we good?