There are enemies and there are hurdles. The former haven't proved too difficult for Korra, who mustered up the power, grace, control, and ingenuity to defeat even a towering, spirit-man Kaiju. It's looking inward to find those heroic attributes that proves difficult — for Korra or anyone with a brain in their head. With “Korra Alone,” Bryan Konietzko and Michael DiMartino pit their heroine against her greatest adversary: herself. Not someone you want to immediately torch with firebending.

[Read our exclusive interview with Konietzko and DiMartino on "Korra Alone" and the final season of 'Legend of Korra' here.]

Much like meditation was the gateway to unlocking the “impossible” airbending skill in Book 1, paralyzed Korra finds herself haunted by a mirror presence, a manifested metaphor that cripples her at every turn. Like a silent Tyler Durden or Ichigo's Inner Hollow from “Bleach,” Korra's Avatar State has become untethered and angry, an individual that isn't mere hallucination. Other spirits can see it. Late in the episode, Glowy Eyes Korra lays the smack down with swinging chains (a Book 3 design holdover I never imagined/am so happy to see continued). The Dostoyevsky double is real and there'll be no balance as long as she's around.

Korra makes progress without defeating her other. Flashbacks to the months after her showdown with Zaheer reveal a distraught Korra who can't even bring herself to begin physical therapy. She's like a war vet come home, near death memories clouding the mere fact that she made it, she's alive. Master healer Katara has the wisdom to turn Korra's frown upside down. Determination is the first step in rehabilitation. The elderly waterbender delivers Tarantino-esque instruction: “Wiggle your big toe.”

Possibility, frustration, and willpower explode from there. Korra will walk again. She'll fight again. She'll bend again. Step by step, we see the Avatar claw her way back to her former self. But she'll never be 100 percent — not with Glowy Eyes staring her down. Though so many of its threads tie back to last season, Book 4 feels inextricably linked to 'Legend of Korra''s opening chapter. The first time we see grown up Korra in Book 1: Air, she's sparring in crimson robes against a trio of firebenders. It happens again in “Korra Alone” (and with the same percussive music cue!). This time, the Avatar struggles, pushing herself in battle, almost keeping up, then falling short when a glimpse of Zaheer flashes in her mind. Somewhere, you just know Glowy Eyes — who or whatever she is — conjures these memories like voodoo doll spells.

Keeping Korra out of “After All These Years” makes “Korra Alone” a concentrated dose of pathos. The road to recovery is long and winding and we feel it when the show show fixes its attention on the arduous journey. There's minimal crossovers from her snail mail correspondence with Mako, Bolin, and Asami; Each voiceover pushes Team Avatar feel further and further apart. Korra can't even bring herself to write back to the boys, confiding diffidence and guilt to her only female friend. Though Korra's encounter with Zaheer didn't directly deal with her femininity, this moment frames the attack in new light. No matter what the circumstances, if a man infringes on a woman, there are shades of the experience that other men just won't understand. It's a beautiful, subtle message for the writers to flirt with.

“Korra Alone” is the perfectly packaged response to all the haters who wonder why the Avatar can't stand up, throw her baggage to the side, and get back to her job.

When Korra decides to depart the Southern Water Tribe to do some global soul-searching, a montage feels like miles. The Avaterverse feels vast as our hero traverses the high seas, volcanic Hell, and mirage-filled deserts, Glowy Eyes appearing on all corners of the Earth. For all the wonder 'Legend of Korra' delivers to screen, it's never captured the scope in a way that melds nature and philosophy. Korra isn't quite the “wandering monk” in these moments, but the loneliness is there, seeing herself as a speck in a huge world to which she is, theoretically, the protector. It's deep, man. When Korra sails ever so close to Republic City, only to turn the sails out of embarrassment, the direction makes feel like there's no place on the planet for Korra to go.

Poeticisms eventually lead into a plot-driven direction that teases Korra's eventual return to Team Avatar. Having nabbed some new threads and cut her hair like a total badass, the episode's non-linear storytelling — a perfect reflection of Korra's chaotic mental state — cascades into epiphany. While dipping her toe into the Spirit World, pudgy, huggable, please-make-these-into-stuffed-animal sprites tell Korra that she's lacking the “Rava Spirit” (duh) but that maybe it's a physical entity that can be obtained again. Back in the physical plane, Korra encounters a puppy, the Snowy to her Tintin, that can see the detached Avatar State. She's not losing her mind. When the dog turns out to be the pear-like critter from the Spirit World, the whole scenario starts to make perfect/absolutely no sense. The episode's major setpiece erupts amongst the trees — all hail the artists who painted the verdant backdrop! — Korra once again coming up short. Glowy Eyes pulls into a pool of the metallic poison, last seen ripping her insides to shreds in “Venom of the Red Lotus.” And then Korra's gone.

Or is she? Did the fight happen? Korra wakes up in a cave, tended to by the one and only Toph Beifong, blind metalbender extraordinaire. "Nice to see you again, Twinkletoes” — the perfect greeting for a reincarnated friend. Last season we learned that familial bickering and a moment of police corruption sent Toph wandering across the land, a life that Korra knows well. Toph was always the pragmatic one on “Avatar: The Last Airbender,” brute force always prioritized over Aang's spirt connectivity. Has that changed? Korra has spirit problems, the Rava-connected Glowy Eyes a real danger to her quest. It's difficult to parse what Toph brings to the table in that conflic. Then again, never underestimate 80-year-old wisdom. Someone has to balance out this spirit talk.

There are enemies and there are hurdles. Kuvira could (will?) land in the first category. Korra's personal definition of purpose looks to be the latter. This Avatar is essential to who she is, maybe. She must live up to the legacy of Aang — a guy who onlookers adore, want to name seaweed wraps after — and the Avatars who came before her, maybe. She, not Kuvira, needs to bring the world together as one, maybe. Glowy Eyes, real or not, embodies expectations — to be sidestepped, conquered or both. The path isn't clear. In that way, “Korra Alone” is the perfectly packaged response to all the haters who wonder why the Avatar can't stand up, throw her baggage to the side, and get back to her job. Life isn't a comic book movie. Neither is “Legend of Korra.”