Some Assembly Required is the second episode of Season One.
A Rude Awakening
After facing the threat of Sendak's Galra warship, each Paladin rests comfortably in the Castle of Lions aside from Shiro, who is exercising, and Keith, who is staring at his wrapped dagger. A sudden alarm blares throughout the Castleship. Allura shouts over the intercom that Zarkon is attacking, alerting everyone to run to the Bridge. The only exception is Lance, who remains sleeping with headphones playing peaceful music in his ears. Meanwhile, Coran overtakes the intercom and melodramatically proclaims Allura's death to make the situation sound more convincing, although it has the opposite effect. Since the Paladins arrive incomplete as a group and out of their Paladin armor (save for Shiro), Allura is frustrated by how unprepared they are, as they must always be ready to fight Zarkon at any moment. Lance's nonchalant and oblivious late arrival only fuels her anger.
Allura explains that she and Coran have been awake for hours and were testing the Castle's alarms as well as the new Paladins, who have failed. Hunk argues that they have been through a lot, flying through space, fighting an evil alien, and eating goo. To put the stakes of their mission into perspective, Allura displays a map of all the distress beacons the Castle of Lions picked up over the past 10,000 years; the grand scale of the map is both stunning and unnerving, showing how Zarkon's empire has conquered almost the entire known universe and will soon attack Earth. With the Alteans readying the Castleship to leave Arus, Allura expects her Paladins to learn to form Voltron before then so they may start freeing every planet conquered by the Galra Empire.
Shiro agrees they must start training, but Pidge wants to speak with the rescued prisoners from Sendak's warship who are recovering inside sleep pods. Coran (while revealing he has everyone ranked by height) reminds Pidge that the aliens need to remain in the pods until the next day. The Paladins head to their respective Lions, each entering a door from the corners of the Bridge to access an elevator, while Shiro accesses an elevator from the front of the Bridge's floor. By the time each Paladin reaches their respective zip-line, they are in full armor. Hunk's zip-line malfunctions as he is riding it because of his weight, so he falls and it continues without him, leaving Hunk disgruntled as he slides along the shaft. The other Paladins reach their Speeders that take them to their Lions, but Hunk's takes off without him as he is late to reach it, so he must continue on foot.
Outside the Castle of Lions, the Paladins wait for Hunk to arrive. Once he does with the Yellow Lion, they fly in sync to bond and form Voltron. While initially excited, the lack of results leaves everyone unenthused. Keith suggests literally stacking the Lions to trigger Voltron's formation like a Lion cheer-pyramid; the first attempt is out of order with the Yellow Lion on top. Hunk denies being a leg last time despite his proclamation "I'm a leg!", claiming he was the head and had been yelling many things. Shiro convinces him to stack the Lions properly. As the Black Lion stands atop the others, Shiro instructs the Paladins to focus themselves into forming Voltron. The attempt is equally futile.
Allura interrupts their attempts and reminds them that they did not form Voltron the previous day until they were in the heat of battle, so she opts to kill two birds with one stone: run a diagnostic test on the Castleship's defenses while inspiring the Paladins to form Voltron. Her method of doing so is attacking them with a barrage of energy blasts from the Castleship's particle barrier. The bombardment sends the Paladins fleeing in a screaming panic, but Allura happily declares how she believes in them and that fear will be their guide.
Lance tries fleeing for the Castle itself and is thrown back by the particle barrier. Hunk begs Allura for mercy, but she declares that Zarkon shows no mercy and sets the Castleship to auto-lock-on mode, leaving the scrambling Paladins to fend for themselves as she heads to work with Coran on prepping the rest of the Castle for launch.
At the Galra Empire's Central Command, Zarkon speaks with the Galra Commander who captured Shiro a year earlier and who sought the Blue Lion on Earth. For his failure to capture the Lion and his choice to preserve the lives of his crew when stationed on a crumbling moon, Zarkon has the commander dragged away. He believes signs of weakness should be cut off rather than allowed to spread.
Zarkon directs his attention to Haggar, asking if she and her Druids have devised anything to capture Voltron. The witch replies that she has been perfecting something so sinister it will terrify all and not even Voltron will stand a chance against it.
Old and New
The Paladins, except for Shiro, lay exhausted in the Lounge of the Castle of Lions as Allura enters with Coran. She is excited to see them because she thinks they successfully formed Voltron and returned, but this is not the case: they flew back inside after the firing stopped and the particle barrier shut down - something Coran admits he had to do in order to test another part of the Castleship. Shiro arrives and scolds the Paladins for taking a break; Allura agrees that the team should be training. Hunk wonders when they will return to Earth instead, and Pidge states that will not happen until the missing Holt family members are found. Shiro reminds them both that Earth will not exist if the Galra Empire is not defeated. Lance laments their inability to fight and form Voltron, prompting Coran to reminisce about the Paladins of 10,000 years prior who fought hundreds of battles together, "tighter than a pack of Yalmors linked at the ears", in sharp contrast to the new rag-tag Paladins.
Back at the Galra Empire's Central Command, with the Druids waiting, Haggar enters a dark cell holding the massive alien Myzax restrained at the neck by two powerful chains. The witch asks him if he would like revenge on "the Champion". Myzax growls in response, steps forward, and smiles a sinister grin.
Coran places the Paladins through intense training at the Training Deck. The Paladin Code states that Paladins must put their team member's safety above their own. Therefore, the goal of their first test is to protect each other from an onslaught of Altean drones.
The Paladins each form a shield on their arm and block a barrage of lasers from the drones. When hit, the Paladin will fall through a hole opened up the floor beneath them. The first to be hit is Pidge, after Hunk instinctively dodges an attack; Hunk himself is struck by a laser after failing to block. With the two gone, Shiro, Keith, and Lance huddle back-to-back to defend themselves and the laser fire increases in intensity. Lance is distracted by verbally jabbing at Keith and by his own ego: when Shiro and Keith crouch to dodge the drones, Lance does not realize and instead lifts his foot, allowing Keith to be struck and disappear. Lance tries defending Shiro on one leg, but leaves himself vulnerable and is struck by a drone. Shiro, left exposed, is finally hit and disappears into the floor. Coran is left exasperated at their utter failure.
The second test is a test of trust: an invisible maze one Paladin who can see the walls on screen must guide another through who cannot see. Lance is the first to attempt the maze, with Keith as his guide; Lance protests out of disdain for Keith and consequently does not listen carefully enough to Keith's instructions, colliding with a maze wall and getting electrocuted. Lance accuses Keith of harming him on purpose and the two argue over the proper instructions. Lance relents and tries inaccurately following them again, but is shocked a second time so he demands to trade places, failing the test of trust.
Eyes of a Lion
The third test is one to test the bonds between the Paladins and the Voltron Lions. From the Castleship's Bridge, Coran instructs the Paladins to fly their Lions into a nose-dive. He then activates Training Helmets on each of the Paladins, causing their visors to go dark and block their vision. The test is to feel what each of their Lions feels and see what the Lion sees to avoid crashing into the ground moments before it occurs - an expert-level test Coran is only putting them through because of the lack of time.
Hunk is overtaken by fear and pulls out of the dive right away. Lance questions if Keith is still diving, and Keith confirms. Lance declares he is speeding up and Keith follows suit. Both of them rush towards the surface of Arus and alarms blare to alert them of the impending crash. Lance further provokes Keith by asking if he is scared, to which Keith finally snaps in anger at the mere suggestion and rushes ahead. Both the Red Lion and Blue Lion crash into the ground with only their rears left exposed. As the Blue Lion rolls away and Keith groans in pain, Lance declares himself the victor.
Pidge panics at the sound of the other Lions crashing and pulls out of the dive, hitting a cliff in the process. Shiro is the only Paladin remaining and flies with his eyes closed. He is able to focus enough to connect with the Black Lion. Once they unite, Shiro witnesses the same scenery the Black Lion sees; he pulls the Lion out of the dive at the last second and is able to fly the Lion through several rocky areas without using his own eyes. Shiro is thus the only Paladin to pass the third test.
As the next test, the Paladins must meld their minds together and mentally form Voltron. They sit in a circle in the Training Deck wearing special headsets to project their mental images while Coran instructs them over the intercom. Each Paladin tries to clear their minds of excess thoughts: Keith thinks of the desert shack back on Earth; Lance thinks of his large family he left behind. Hunk thinks of food while Shiro remembers the Kerberos Mission launch. Only Pidge's mental projection is obscured heavily by static, but is the photograph Hunk found earlier and claimed was of Pidge and a girlfriend. The Paladins focus on projecting an image of their Lions and forming Voltron with them. Pidge struggles and cannot manifest the Green Lion. Keith opens an eye to watch Pidge and finally breaks focus to scold Pidge for thinking of anything else. Pidge loses focus and accuses Hunk of mentally rooting around and causing the problem.
Coran scolds the Paladins for not letting each other into their minds. The Paladins try again and Pidge is able to manifest a projection of the Green Lion. Although all seems well as the mental Voltron starts to form, the Green Lion reverts to the same static-filled image as before and Pidge finally snaps, throwing the headset off. Pidge exclaims how invasive and undesirable it feels to share minds. Shiro tries to calm Pidge, as the Paladins were making progress, but acquiesces they all should take a break when Pidge excuses the angry outburst as just a symptom of being tired.
The Tyrannical Princess
While the Paladins take a break in the Training Deck, sipping water from sealed pouches provided by Coran, Allura catches them in the act and demands an explanation. She repudiates Coran's philosophy of not pushing too hard, and orders the Paladins to face the Gladiator: an Altean fighting robot that uses a staff as a weapon with a painful shock.
With their Bayards formed, the Paladins await the Gladiator's arrival in the Training Deck. The final test is for the Paladins to fight as one. The Gladiator robot drops from the ceiling and Hunk panics; he rapidly fires his cannon but cannot lift it from the floor, so the bullets miss the robot and nearly hit Keith instead, who defends himself with his shield. Hunk is overtaken by the Gladiator and knocked out. Pidge attempts to fight the Gladiator alone and is also taken out. Next, Lance fires his rifle at the robot; the Gladiator knocks Lance's Bayard aside and strikes Keith as he attempts to intervene, then hits Lance solidly on the head and swings the Blue Paladin into Keith. The two are left sprawled on the floor as Shiro prepares to face the Gladiator alone.
However, when the Gladiator rushes forward, it triggers a memory in Shiro of Galra Sentries rushing him some time in the past. Shiro freezes, left defenseless by his own mind. As the Gladiator jumps above to deliver a powerful blow, Keith reappears to block the strike for Shiro and asks if he is alright. Shiro does not respond; this minor distraction is all the Gladiator needs to parry Keith's Bayard and send him flying into Shiro, both out of commission and ending the final test in failure.
Allura approaches them with a sour look on her face and claims the fight simulator was set to a level easily handled by an Altean child, and berates the Paladins for being nowhere near a team capable of fighting Zarkon.
Allura the Terrible
The Paladins sit in the dining hall before a table filled with food goo and other strange foods. Coran calls it focusing food to help them form Voltron. As they prepare to enjoy the meal after a long day, Coran suddenly pulls out a device that triggers the Paladins to each be handcuffed to another: Shiro with Hunk, Hunk with Lance, Lance with Keith, and Keith with Pidge. Shiro and Pidge are also secured to their chairs. Feeding each other is the true final bonding test, as they have not learned to work as a team yet.
Back at the Castle of Lions, Allura has joined the Paladins for dinner. The Paladins struggle to eat. Lance is at the mercy of Hunk's love of food; he twitches and knocks the goo out of Hunk's spoon, then ends up with his hand inside Hunk's mouth and nose. His reaction to pull away only ends up pulling him towards Hunk as the Yellow Paladin continues to eat. This drags Keith's hand into Lance's food goo, much to both's disgust. The ensuing complaints on the sheer absurdity of the situation earn Allura's wonderment if Earthlings ever cease complaining.
Shiro tries asking the princess to allow the Paladins to have an actual break; Keith and Lance reaffirm this by declaring they are not prisoners for the Allura to toy with. Coran scolds them for yelling at the princess. Pidge questions what Allura is even the princess of, since she is not one of Earth nor any planet. As punishment, Allura flings food goo at Pidge, directly to the face.
A moment of pause falls across the dining hall, with Pidge and Keith glaring at Allura. Keith finally loses his temper entirely and throws a bowl full of goo at the Altean princess. Coran intervenes to block it and tosses a mass of goo across all the Paladins in return. Hunk declares the battle is on and spews food goo at the Alteans from his mouth. The ensuing food goo fight quickly turns from frustration to enjoyment as everyone begins laughing and working together to take revenge on Allura and Coran.
A Team Bonded
Allura is left exhausted after the ordeal. The Paladins look at each other and laugh at the mess they are. Allura's sudden angry question if they realize what is going on brings a feeling of incoming retribution, but the princess happily smiles at them and points out the Paladins have finally bonded and worked together as one. Keith admits she is right, and Lance admits he does not hate Keith at the moment. Hunk asks if they are all thinking the same thing. While Shiro replies they are going to form Voltron, Hunk admits he was thinking of dessert, but is ready to form Voltron too. His ensuing cheer causes the Paladins to all fall over because they are still handcuffed together.
The Paladins clean up and leave for their Lions. This time, Hunk is able to reach the Yellow Lion properly. The excited Paladins launch their Lions from the Castleship and successfully form Voltron in one go. Allura looks on and tells Coran she knew she could make them bond; all they needed was a common enemy. Coran agrees that a man can be driven to do anything if a beautiful woman is really, really mean to him. Allura is not amused.
That night after returning to the Castleship, the Paladins sit in the Castle Lounge recounting their success and newfound bond. Lance thinks he is too excited to sleep; Keith is pleased with the day but ready for lights out. Hunk, overflowing with affection, embraces them both and declares them all brothers with no secrets nor any barriers, and that he loves them all. Shiro sees this and pats Pidge on the shoulder, who quietly pats the Altean Mice. Keith wonders if G-forces messed with Hunk's head because of his claims, and Hunk sheepishly admits that might be true, but it has been a rough few days for him. The Paladins begin to leave for their rooms but Pidge remains on the couch. At Shiro's questioning, Pidge calmly reassures him the young Paladin will follow the rest to sleep soon. Shiro congratulates Pidge for the good work done that day helping the team come together, then leaves.
Once left alone, Pidge frowns and looks at the photograph that had appeared during the mental training earlier. It is clearly of a girl and a boy with similar appearance to Pidge's but neither seem to be the Green Paladin.
At the Galra Empire's Central Command, the Galra prepare to launch the Galactic Gladiator. Zarkon declares the Robeast will destroy the Paladins and enable him to finally claim Voltron. The Robeast is launched into space with the destination of planet Arus.