Korra and Tenzin, all fired up from recent events, vigorously train for the coming battle with Unalaq. Deeming that Korra has more important things to worry about — not to mention her aggressively beheading a training dummy — Mako declines to resolve their relationship problems for the time being.
The gang meets with Katara and Senna, who reveal Tonraq's capture. After delivering Jinora to Katara, who begins to attempt to save her granddaughter's life, the gang discusses their next move, with Harmonic Convergence only hours away. Bumi is able to suggest an attack on the southern portal from above (in his roundabout way), which ends up failing and results in the majority of the party getting captured except for Bumi himself.
Unalaq approaches his prisoners, and reveals that when Harmonic Convergence comes and Vaatu is freed, he will merge with the dark spirit and become a Dark Avatar, and will conquer the world. Tonraq pleads for Unalaq to stop for the sake of his family and humanity, but Unalaq ignores him and goes off to achieve his destiny.
Bumi recovers from the battle, and is able to tame a Dark Spirit with his flute. Recruiting Naga to help him, he attempts to sneak into Unalaq's encampment to free his family and friends. The Dark Spirits attack him, and through sheer blunder and luck, Bumi manages to destroy the camp and free his comrades.
Seriously. It has to be seen to be believed, go buy the DVD.
Korra instructs Asami to take Tonraq to Katara to be healed, and prepares to enter the Spirit World with Mako, Bolin, Tenzin, Kya, and Bumi. Tenzin and his siblings are to go search for Jinora the moment they arrive, while the Fire Ferrets will take on Unalaq and Vaatu.
The group is almost immediately attacked by Unalaq, who is able to stall them just long enough for Harmonic Convergence to begin, and for Vaatu to be freed once again after 10,000 years of imprisonment.
Tropes in this episode include:
- Ace Pilot: Asami strafes Unalaq's base camp with her fighter plane, dodging the anti-air artillery and destroying much of its defenses. It's not until Desna and Eska come into play that she is taken down.
- The Bad Guy Wins: Korra is unable to close the spirit portals in time to stop Vaatu's escape.
- Demolitions Expert: Bolin gets a backpack full of plastic explosives which he bends at his targets then detonates remotely.
- Downer Ending: The episode closes on Vaatu's escape.
- Evil Counterpart: Unalaq plans to become the Dark Avatar by fusing with Vaatu.
- Evil Is Not a Toy: Tonraq makes this argument to Unalaq about what could potentially happen if the latter fuses with Vaatu.
- Fusion Dance:
- Some dark spirits do this while trying to impede Korra and company from reaching the portal.
- Unalaq's ultimate plan is to do this with Vaatu and become a Dark Avatar.
- The Greatest Story Never Told: Bumi, through bumbling and sheer luck, manages to completely wipe out the Northern encampment guarding the portal. However, given his previous tall tales, he decides they'd never believe how he did it and chooses not to explain.
- Haunted Technology: It's shown dark spirits are capable of taking over machines, like a mecha tank.
- Hope Spot: After they're taken prisoner, Korra tries to reveal the truth about Vaatu to her Uncle. Her hope is that Unalaq has been duped, that he doesn't realize he's partnered with a being of pure evil, and that this revelation will snap him back to reality. Unfortunately, it's quickly dashed as Unalaq confirms he knows damm well who and what his partner is...and doesn't care as it's intrinsic to his plans.
- Ignored Epiphany: It's rather subtly done, at least by the standards of the series, but the glances Desna and Eska exchange when they hear about Unalaq's Dark Avatar plans show that 1) this was news to them, and 2) they are dismayed by this news. However, they still remain loyal to him, trusting that he knows what he is doing.
- Let's Split Up, Gang!: Asami takes the injured Tonraq back to Katara for healing on Oogi. Tenzin and his siblings split off to find Jinora in the Spirit World. That leaves Korra, Mako and Bolin to fight off Unalaq and Vaatu.
- Meaningful Look: Eska and Desna shot each other and their father ones after Unalaq reveals his insane plan to merge with Vaatu and become a Dark Avatar.
- Mugged for Disguise: Bumi jumps one of the mooks and uses his suit to sneak into the camp.
- Music Soothes the Savage Beast: Bumi's flute calms the spirit he tackled off of Oogi. Unfortunately, the ones in the Northern camp are just riled up by it.
- No-Sell: Bumi is a Badass Normal, but nothing he throws at the dark spirits has any effect. It's only when he plays his flute that one calms down somewhat.
- Obnoxious In-Laws: A Northern Tribe soldier cites this when voicing his uneasiness around the dark spirits.Soldier: Ya know, if I wanted some ball of evil lurking over my shoulder all the time, I'd have stayed home with my mother-in-law.
- O.O.C. Is Serious Business: Lampshaded by Kya when she points out Tenzin is making overly aggressive suggestions for dealing with the blockade. Bumi, being a military man, knows from experience that whatever Tenzin suggested is a tad overkill (and suicidal!).
- The Reveal: We find out that Unalaq wants to become a dark version of the Avatar by performing a Fusion Dance with Vaatu. That's the Evil Plan.
- Slipknot Ponytail: After Oogi crashes and they're captured, Korra's ponytails come ondone. She remains like this for the rest of the season.
- Strategy, Schmategy: Bumi manages to clear out the guards near the spirit portal with random manuevers that blindside the soldiers because they are unexpected.
- Taking You with Me: Bumi gets one of the dark spirits off Oogi by grapping it and falling off.
- Tempting Fate: Mako does this when he says that the soldiers won't see their attack coming. The problem is, it didn't occur to him that the soldiers have the aid of the Dark Spirits.
- Well-Intentioned Extremist: Unalaq honestly seems to believe that releasing and merging with Vaatu is the best course of action for the world. Balance and all that, you know?
- When the Planets Align: This is the episode where Harmonic Convergence occurs. There's a scene of the planets coming together.
- You Are Too Late: Korra falls short a few seconds when trying to close one of the portals, allowing Vaatu to escape.
- You Can't Thwart Stage One: Korra is unable to stop Vaatu from escaping. In a case of playing with a trope, she still has time to re-seal him before he merges with Unalaq.
