What is a Traitor? (裏切り者って、なに, Uragirimono tte, nani) is the third episode of the SSSS.Dynazenon series.
Monster of the week: Burnaddon (バーナドドン, Bānadodon)
One of the Kaiju Eugenicists, Juuga, tells Yomogi that they were betrayed by Gauma. Yomogi and the others become distrustful of Gauma but they end up having to fight a Kaiju with their hearts in disarray. With their hearts separated, Dynazenon is unable to unleash its full power.
Picking up from where the previous episode left off, the group and Kaiju Eugenicists come face-to-face in a tense confrontation, as Gauma disagrees with their use of kaiju to wreak havoc. To the shock of Gauma's fellow Dynazenon pilots, Juuga brings up the fact that Gauma used to be one of the group's own and offers to welcome him, but is opposed by Onija who already vowed to make their comrade pay for their desertion. The tension soon break when Yomogi's clumsiness sees him pressing a button on his controller which resulted his Dynasoldier to blow a gust of wind from its nostrils, nearly blowing the enemy group off the bridge. Nevertheless, Kaiju Eugenicists decided to make their leaves since they already lost the current battle.
On the next day in the morning at their usual training spot, for missing his training, Yomogi had to master his Dynasoldier under Gauma's watch. Chise expresses little interest for school, but nevertheless expresses her desire to be like Koyomi who argues that he did go to middle school prior. During the training, Yomogi got distracted by conversation between Gauma and Kaiju Eugenicists which explicitly showed that they shared a history together, resulting his Dynasoldier to be tripped.
Later at the school, Yomogi and Yume go for the music prep room, explaining that her late sister Kano joined chorus club in her lifetime as she wants to know more about her. The advisor who in charge of the room states that they should ask Kanae instead. As they waited for her, Yume explained that Kano died just before a recital five years back, and the latter's invitation for such recital was the actual instance of them truly interacted with one another.
Just then, Yomogi got a call from Awaki, Nazumi, Ranka, and Kaneishi to hang out at the communal park on top of a building. As they do, the latter four are discussing about the second kaiju attack with Awaki remarking Yomogi seemingly indifferent about it (unaware that his friend was the one who stopped it alongside his fellow Dynazenon pilots). Just then, Juuga unexpectedly shows up to ask Yomogi to talk with him in private. As they leave, Nazumi remarks that Yomogi hangs out with weird people lately.
Meanwhile, Gauma is working with a sign that leads to Model Apartments, complaining that he's starving. Koyomi is still waiting for Kanae, the chorus club graduate who knows Kano, when Mei meets her. Mei worries whether it's okay to meet that person on her own, leading Yume to remark her as her mom again.
While strolling around the city, Koyomi meets Inamoto who turned out to be his middle school classmate. He remembers her as a troublemaking girl who damaged the school's windows by hurling rocks at them. During the awkward interaction between middle school friends, Inamoto reveals that she has recently married and subsequently moved back to the city, a news that disheartened him somewhat. Upon being asked whether he has found himself a girlfriend yet, Koyomi quickly denies, but nevertheless agrees to exchange their phone numbers. After Inamoto left, Chise, who overhears the whole thing, begins to tease her cousin for it.
Back to Yomogi and Juuga, the latter tells the former that he, his fellow Kaiju Eugenicists, and Gauma were Kaiju Users from 5000 years back revived in modern era for reasons they yet to discover and he used to look up on Gauma as his role model. Juuga further states that Yomogi should ask Gauma himself about why they had a fallout to begin with before the young man makes her leave for an errand. As Juuga returns to his comrades on top of a nearby water tower, Onija questions why he didn't kill the young man straight away. Juuga rationalizes that it would be better if the group they currently fight against join them for a common cause instead of destroying them. Sizumu states that neither of them was able to control Dynazenon in which Mujina corrects that the mech is not a kaiju, but rather something else entirely. Onija, on the other hand, only cares about destroying their opposition. Meeting up with the others after being reprimanded by Inamoto for his absence on the other day that night, Yomogi informs the others about what Juuga told him regarding Gauma. Yume asks him which one he trusted most between the two, in which Yomogi confessed neither since he barely knows them at that point. Chise suggests that they should ask Gauma personally for answers, thus the group set out to meet him at his residence, a tent built beneath the bridge where he and Yomogi first met. Other than the fact that Kaiju Eugenicists is driven by the will of kaijus as they wreak havoc upon humanity (something Gauma had since disagreed with), Yomogi and co. learned nothing from their friend, worsening their doubts toward him. Before they could ask him further, Gauma makes his leave since he already has a job to do, which turned out to be another of his part-time ones, this time a traffic control laborer.
On the next day, Kaiju Eugenicists activates another of its kaiju, this time a bipedal one which possesses the power to produce volatile sparks that Onija control after awakening it from its dormancy at one of transmission towers in Chiba prefecture. Yomogi and Yume soon informed about the situation by Gauma, surprising the former due to the considerable distance until the latter reminds him that they can reach the area with their Dynazenon components. While on their way for the scene with Dynasoldier on top of Dynadiver while riding it, Yomogi once again attempts to ask Gauma about his motives once again only to be given a cold shoulder. It doesn't take long for Gauma's secretive nature to ultimately hold the group back thus preventing them from combining into Dynazenon, though that doesn't prevent them from ignoring their enemy. Eventually, after they evaded the bipedal kaiju's stronger blast by Yomogi having his Dynasoldier holding both Dynastriker and Dynadiver tight while clinging onto Dynawing at the safer distance on the sky, Gauma confessed that he wanted to reunite with the mysterious woman who entrusted him Dynazenon in the first place before apologizes.
With the trust between the group reaffirmed, Yomogi, Gauma, Yume, and Koyomi combine their respective Dynazenon component into Dynazenon and proceeds to try to engage the bipedal kaiju in melee, but it was not enough because their opponent showcases its ability to overlap its explosions into sort of barrier to repel the mech. Realizing their enemy's explosive power only works in areas with air owing to its incendiary nature and Koyomi reminds the group that Dynazenon can fly, Yomogi and co. rally the mech to charge upon the bipedal kaiju once again, this time with their hearts united as one while toppling their opponent to disorient it before taking it with them to the outer space. As soon as they confirmed the bipedal kaiju's powers being useless there, Gauma and his fellow Dynazenon pilots exhaust everything they got to obliterate their opponent, blowing it into pieces. Undeterred, Onija launches the bipedal kaiju's surviving head in a bid to destroy Dynazenon only for the mech switches to its Dyna Rex configuration to crush the head with its draconic jaw and suppress its explosion at the same time. To add insult to injury, the bipedal kaiju's surviving remains rain down upon Onija while his cohorts calmly make their leave.
In the aftermath of the battle, Gauma tells the group his side of story about his and Kaiju Eugenicists' past before suspecting that Dynazenon's original owner might've been revived alongside them as well. As of their resurrection, that could be attributed to kaijus they fight which existence defy common sense. As night comes, the humiliated Onija gets on his feet, bewildered by his near-death experience.
- The episode reveals Gauma and Kaiju Eugenicists' history as an ancient band of Kaiju Users from 5000 years ago as well as the former's encounter with his benefactor who entrusted him Dynazenon, which unfortunately led to him and the group became bitter enemies following their revival.
- 3.3: A Space Souvenir (宇宙のお土産, Uchū no Odosan)
- The Dynazenon pilots talk about places they have been to, and Koyomi gives Chise a "souvenir" from space: a lottery ticket left in his pocket.