"The Terror Within" is the eighth episode of Book Three: Change of The Legend of Korra and the 34th of the overall series. It aired on July 25, 2014, for attendees of The Legend of Korra panel at the San Diego Comic-Con, and on Nickelodeon the same night.
As Opal leaves for the Northern Air Temple to start her airbending training, Zaheer and his gang try to kidnap Korra in Zaofu. Although Korra's friends are able to save her following a climactic fight, the group comes to suspect that someone inside Zaofu actively conspired to allow the Red Lotus to infiltrate the city. After an extensive investigation, Team Avatar discovers evidence that Aiwei, Suyin's trusted advisor, is the traitor; upon realizing that they suspect him, Aiwei flees the city, using a bomb to cover his escape. That night, Suyin gives them a jeep, and Team Avatar departs Zaofu, intending to hunt down Aiwei.
In Zaofu, Wei and Wing train Bolin and Korra in the art of metalbending. Wing launches several chunks of metal at Korra, who dodges them and retaliates by sending a metal cable snaking toward him. Wing avoids it and, by taking control of the attack, manages to knock Korra over, capturing her with her own cable. He expresses excitement and disbelief that he is sparring with the Avatar, while Wei voices his disappointment over being stuck with Bolin, who is unable to metalbend a meteorite despite his efforts. Fed up, Wei crushes Bolin between two metal plates before sending a meteorite at his head, announcing with amusement that the best way to learn is by practice. Defending himself, Bolin ducks underneath the meteorite and retaliates by striking his opponent in the middle of his forehead with a pebble, earning himself a compliment from Mako, despite his emphasis on the fact that the purpose of the session was to practice metalbending. While Bolin tells his brother that learning metalbending takes time and considerable effort, Korra manages to get back on her feet, wrapping her cables tighter around her before unleashing them with more force, sweeping the feet from underneath Wing and winning her match. As she smugly announces that she is the "metalbending champion", Bolin dismisses her success with annoyance, attributing it to her being the Avatar. Asami remarks that it is almost time for Opal's farewell dinner, causing Bolin even more distress.
In the dining hall, the chef presents Opal with her favorite meal and expresses how much he is going to miss her, as she is the only one who appreciates his raw vegetable wraps. Bolin dismally remarks that he will think of Opal every time he sees raw kale, expressing how unfortunate it is that Opal had to leave just as they were getting to know one another. Opal reassures Bolin that they will be reunited soon enough, and the two share a vegetable wrap while gazing into each other's eyes, a moment which Varrick interrupts to offer Bolin some relationship advice, which he promptly declines.
Varrick is unfazed by Bolin's choice and orders Zhu Li to bring his new invention, an "airbender finder", which he shows Asami. Curious to see whether the invention works, Asami tests the device on Korra, but is ultimately disappointed when the device fails to respond. Varrick grabs his invention in frustration, stating that it only works when an individual is airbending. On the other side of the table, Mako attempts to join Varrick and Asami's conversation, but is frustrated over not being seated near his friends, leaving him unable to hear anything. Suyin calls for everyone's attention and expresses how proud she is of Opal's decision to leave for the Northern Air Temple, causing Wei and Wing to become emotional, much to Huan's annoyance. After a brief toast, Suyin and the others bid farewell to Opal and watch as she leaves Zaofu aboard an airship. Once the airship takes off, Kuvira uses a radio to instruct the other guards to seal the city off for the night, while Lin tells the others that they will be departing the following morning.
That night, Zaheer and his associates infiltrate the city and eventually make their way to the guesthouses by Suyin Beifong's estate. Despite their efforts to remain undetected, the four startle Pabu, who begins to cry out in distress; his high-pitched screeches are dismissed by a tired Bolin. Outside of Korra's room, Ming-Hua uses ice to cut a small circle from the window. Zaheer fires three shirshu-spit darts at Naga, subduing her, but not before the polar bear dog manages to growl, waking Korra. She becomes aware of the group's presence and attempts to use firebending to attack her opponents, but is quickly shot with a dart, paralyzing her instantly and allowing Ghazan to carry her over his shoulders without opposition.
Outside of Bolin and Mako's room, Pabu notices the four criminals again, and cries out enough for his owner to become aware that Korra is slung over Ghazan's shoulders. Waking his brother, Bolin races outside with Mako to attack the four criminals and are immediately overwhelmed by a continuous barrage of bending attacks. However, the commotion draws the attention of the guard, and upon Mako's warning that the intruders have kidnapped Korra, they raise the alarm. As several spotlights hone in on the four criminals, Ming-Hua remarks dryly that the group's attempt to utilize the element of surprise has failed. Ghazan calls to initiate the back-up plan, inciting P'Li to begin firing several combustion beams aimed toward the guards as well as the two brothers. Bolin and Mako are thrown back by the impact of the blast, with the latter asserting that they could not allow the four criminals to leave the city with Korra. Asami attends to the two brothers and remarks that they will not be able to escape easily, as Lin begins to surround the four with metal panels. Suyin and other members of the Metal Clan begin to follow her lead, effectively trapping Zaheer and his associates inside a makeshift metal prison. Kuvira orders the four to surrender and release the Avatar, just as the ground surrounding the makeshift prison begins to turn into a moat filled with lava. Bolin expresses his excitement over seeing a lavabender, but soon realizes that Ghazan's ability will make it more difficult for them to retrieve Korra.
Zaheer attempts to use airbending to cover himself and his associates with a cloud of smoke, but he is restrained with metal cables and pulled away from the moat. Several guards attempt to subdue the airbender, to no avail. As numerous attempts to cross the moat prove unsuccessful, Suyin and Lin resolve to drop down from the top of the metal dome on cables, instructing Bolin to temporarily stun P'Li by striking her third eye with earth. Despite issues with their timing and communication, Bolin manages to block P'Li's chi while the two metalbending sisters retrieve Korra, much to Zaheer's outrage. Despite the airbender's attempt to pursue Lin using his airbender staff, Zaheer is eventually grounded by Suyin, who uses metal shards to pierce his glider. Realizing that they failed, Zaheer conjures a large air dome, which gathers enough smoke to cover his, and his group's, escape.
Back in Suyin's estate, Aiwei administers an antidote to neutralize the shirshu toxins in Korra's systems, allowing her to regain mobility instantaneously. Lin reprimands Suyin for allowing a breach in her city, though the latter denies any involvement in the incident. Aiwei insists that someone from inside the city must have helped Zaheer and his associates enter the city, to which Korra agrees, insisting that it must have been one of the city's guards. Per Suyin's orders, Aiwei interrogates everyone from the guards to Varrick, whose description of his nightly routine leaves his interrogators annoyed. At Lin's insistence, Suyin herself is also interrogated, but Aiwei finds them all innocent until he questions Hong Li, whom he accuses of lying. A furious Suyin berates Hong Li for betraying the clan, and demands he tell them he knows about Zaheer, from how Zaheer and his group got in to their current whereabouts. Aiwei suggests searching his home, where the group finds a note from the four criminals and a copy of the guards' logbook. Convinced that Hong Li is guilty, Mako suggests confronting the guard with the evidence, but he is surprised when Aiwei announces he intends on delaying the interrogation.
While examining the crime scene, Mako begins to question whether Hong Li is responsible for aiding Zaheer and his gang, as it is improbable for him to have been involved with the group due to his relatively young age. Korra reiterates that the evidence against Hong Li is overwhelming, prompting Varrick to suddenly appear and remark that it is almost "too overwhelming". Bolin greets Varrick and asks why he is exploring the crime scene. The mogul replies that he is collecting pumice stones, intending to treat his calluses by having Zhu Li rub his feet with the lava rocks, much to Team Avatar's disgust. Mako urges Varrick to expound on his comment about the evidence, prompting him to reply that the case is clearly a conspiracy. He remarks that accusing someone and planting evidence in that person's apartment is a guaranteed way of setting him up. Mako compares the current situation with what Varrick did to him and deduces that Hong Li is an ideal fall guy for Aiwei, the only person capable of keeping secrets in Zaofu.
Team Avatar heads to Aiwei's residence and proceeds to search it for evidence, intending to compromise the official and prove his involvement with Zaheer. When Bolin picks up a jar from a shelf, Mako orders him to put it back, knowing they do not want to leave any traces of their visit. The earthbender cannot remember the exact placement of the object, however, prompting Mako to return it to what he believes to be its rightful place himself. By doing so, Mako notices scuff marks on the floor and theorizes that they were made by the bookshelves sliding open. Testing his theory, he pulls at the side of the furniture, successfully revealing a hidden staircase leading down to a door behind it. Before the group can explore the premises, Asami warns them that Aiwei is on his way home, and Mako hastily closes the bookcase.
Entering his home, Aiwei is surprised to find the foursome waiting for him, and demands to know the reason for their break-in. After Bolin tries to cover their intentions with a transparent lie, Korra explains that things were not adding up, and that they came to his house looking for more satisfactory answers. Aiwei invites the group to sit, declaring that if they desire to talk, they should do it while drinking tea. Pouring the teenagers a cup each, Aiwei walks away from them, asking what exactly was not adding up, reiterating that Hong Li was "clearly lying", referring to the evidence found in the suspect's apartment as proof. Mako counters by placing emphasis on the guard's age, explaining that his youth, compared to the age of Zaheer and his group, implies no clear link between the two parties. Walking further away from the team, heading toward his bookcase, Aiwei muses that the link could have come from a family tie, or possibly a bribe, and concludes that they will find out Hong Li's reasoning in time. Understanding that they do not suspect Hong Li, Aiwei asks them who they suspected of committing the crime instead; after the team exchanges a few uneasy glances, Asami answers that they do not know. Aiwei subsequently asks whether or not they think he had something to do with it, while placing the jar Bolin had picked up earlier back in its rightful place. As Korra glares at Bolin, she answers that they are merely looking for answers. Aiwei asks if they think they found something, noticing that his bookcase is slightly out of place. Glancing over his shoulder toward them, he warns Korra that she has no idea what is coming for her.
Suddenly and unexpectedly, Aiwei lifts a metal wall between himself and the others; Mako quickly sends a fireball in his direction, but it dissipates against the thick metal. Korra surges forward and punches the metal, denting it. As Mako urges her to work faster, Korra snaps at him to "back off", and after a few more tries, she tears a hole in the wall large enough for them to walk through. They descend the stairs to the door they found earlier; as they enter the room, they trigger a barrel which Aiwei has rigged with explosives, causing it to detonate. The large explosion that follows decimates everything in its path, and is noticed far outside Aiwei's house, alerting the patrolling guards.
Inside the basement, Korra has managed to protect herself and her friends from the inferno by surrounding them in a ball of air. Venturing further inside the now destroyed room, the team concludes that Aiwei has escaped through a tunnel. As Korra and Bolin clear out the path, Lin and Suyin, having been alerted by the explosion, run inside the room and ask what happened. Korra explains that Aiwei lied about Hong Li to hide the fact that he allowed Zaheer and his team to enter the city, and that when confronted about the matter, he "bolted" through the tunnel in the room. Lin, using her seismic sense, deduces that Aiwei must have collapsed the tunnel on his way out. Mako adds that the truth seer also rigged an explosion to destroy any evidence that might have been in the room to corroborate their suspicions. Korra concludes that this room was Zaheer's passage in and out of the city, and labels Aiwei definitively as the traitor. As Kuvira runs in, asking if everyone is all right, Lin announces that Aiwei is a fugitive and orders her to assemble all available guards to search the mountainside and discover where the collapsed tunnel exits. When Kuvira leaves, Lin places a comforting hand on her sister's shoulder. Later that night, Kuvira returns to report that they had found the exit of the tunnel, though there was no sign of Aiwei beyond some fresh tire tracks, leading Mako to deduce that he had a plan prepared in the event that he was discovered. As Kuvira leaves, Suyin, devastated by his betrayal, laments that her trust in Aiwei was misplaced, realizing that one of her most trusted advisors has indeed betrayed her.
Mako expresses how dangerous Zaheer and his associates are, prompting Korra to decide to hold off the group's search for airbenders in favor of tracking Aiwei as well as Zaheer's group. Lin sharply disapproves, insisting that Korra return to Republic City for protection. Korra protests, noting that if she is not safe in Zaofu, she is not safe anywhere, leading Lin to reiterate that she cannot, as it would be more dangerous to pursue him. Korra snaps that Lin needs to stop trying to protect her, as it is her job as the Avatar to deal with people like Zaheer, and Lin responds angrily in turn that Korra should not lecture her about jobs. Suyin breaks up the argument, telling Korra to listen to Lin, who is simply looking out for her, and promises Korra that Aiwei and his allies will be found and brought to justice. Korra reluctantly relents, and agrees to retire to her room for the night while her friends with her friends.
Some time later, Suyin visits Team Avatar at their guest house. Asking for confirmation that Naga can really track down Aiwei, she provides the group with a key to a jeep parked outside of the city. She explains to the group that her earlier support of Lin was a distraction to buy them time, and that she wants nothing more than to have Aiwei tracked down and returned to Zaofu. She urges the group to leave, promising to deal with her sister herself in the morning. After thanking Suyin, Korra and the others head out in search of Aiwei.
- Janet Varney - Korra
- David Faustino - Mako
- Mindy Sterling - Beifong
- Seychelle Gabriel - Asami
- P.J. Byrne - Bolin
- John Michael Higgins:
- Guard #3
- Henry Rollins - Zaheer
- Alyson Stoner - Opal
- Anne Heche - Su
- Dee Bradley Baker:
- Jeff Bennett - Radio broadcaster
- Grey DeLisle-Griffin - Ming-Hua
- Maurice LaMarche:
- Marcus Toji:
- Peter Giles:
- Guard #1
- Zelda Williams - Kuvira
- Joey Richter - Hong Li
- Main article: Transcript:The Terror Within
- Main article: Writing in the World of Avatar
- Zaheer used shirshu-spit darts to sedate Korra and Naga. The darts were also the same type used by the beetle-headed merchants to subdue Appa in "Appa's Lost Days".
- Suyin urged Bolin to temporarily stun P'Li's third eye, which blocked her chi and weakened her combustion. This technique was first used by Toph Beifong in "The Runaway", when she inadvertently stunned Combustion Man after a stray pebble from her attack hit him in his third eye.
- Mako recalls the time he was framed by Varrick in "The Guide".
- Korra employs a style of earthbending used by both Toph and Aang while trying to pry open the metal wall, by flicking her wrists inward rather than with a full fist.
- Aiwei is a mole for the Red Lotus.
- At the start of the dinner, only Opal is served a raw veggie wrap while everyone else is served fish. However, when the scene pans to Mako, everyone else also has raw veggie wraps on their table.
- One of the guards uses both earth- and firebending while battling Zaheer.
- After Lin and Suyin make it back to the top of the dome, Korra is lying between Lin and the hatch. In the next shot, Lin and Korra have switched positions.
- "The Terror Within" was the last episode of Book Three: Change to debut on television, as the remaining five episodes premiered online through several digital platforms before airing on Nicktoons during the week of October 6, 2014.
- This is the only episode in which P'Li is seen generating normal fire.
- Lin's use of the phrase "third-eyed freak" mirrors Katara's when she described Combustion Man in "The Runaway".
- This episode marks the first time that seismic sense is used by an earthbender in footwear, as all previous uses of the technique involved being barefoot to increase the user's connection with the earth.