The Fall of the Castle of Lions is the fourth episode of Season One.
The Greatest Weakness
The Voltron Alliance
After the defeat of the Galactic Gladiator, Team Voltron celebrates with the people of Arus inside the Castle of Lions before the team must depart to continue the fight against Zarkon. Happiness clouds the atmosphere of the Castle's vestibule as the Arusian King presents the team with a reenactment of the battle against the Robeast. Allura, unimpressed but remaining polite, presents the Arusian King with a communicator that can be used to contact the Voltron team for help at any time and declares Arus the first planet within the new Voltron Alliance.
The Arusians cheer at the declaration. Hunk suggests to Lance and Keith that they should have their own team cheer. Lance attempts one, but Keith fails to catch on and only continues to misunderstand his part in the cheer. Giving up the attempt, Lance tries drinking Nunvill, an alien drink purported to be the "nectar of the gods", and finds it tasting horrid like a mix of hotdogs and feet. Coran is able to drink the strange substance with ease and displays how Nunvill is also a useful hair tonic by splashing some on his mustache to make it flourish. The royal advisor leaves; Lance tries the foul drink again. Unfortunately, he is unable to stomach the drink and becomes unresponsive while standing. Keith and Hunk watch over him in bafflement. When Keith taps Lance ever so slightly, the Blue Paladin falls over.
Shiro is watching the entrance of the Castleship because he is concerned another attack from the Galra Empire could occur at any time; they are vulnerable with the Castle doors left wide open to allow the Arusians to move freely about. He expresses this concern to Coran. Despite their mischief, Coran considers the Arusians harmless and thinks they should be allowed to enter the Castle that has occupied their planet for likely 10,000 years. Shiro is not abated and leaves to check the perimeter of the Castle.
The Commander Lives
Outside on Arus, as Shiro feared, Sendak is secretly observing the Castle of Lions and is fully aware of how vulnerable Team Voltron has left themselves. Haxus notifies him that Sentries are in position around the Arusian village for their plan. Sendak thinks it will be easy for Haxus to infiltrate the Castle with how open it is. His fellow soldier does not think that will be necessary, as he spies Pidge with the repurposed Galra drone, Rover. Haxus plans to copy Rover's code and slip in a bomb drone disguised as Rover to infiltrate the Castle undetected instead. Sendak is pleased with the idea, and Haxus leaves to initiate their plot.
An Uncertain Team
Allura, unaware of the impending threat, overlooks the party with the Altean Mice. She speaks to the mice about her anxiety regarding the huge mission they are undertaking with inexperienced Paladins who hold the fate of the universe in their hands. She watches Keith spit out Nunvill on Hunk, who returns the accident with a joke about his eyes being harmed; both Paladins laugh. Unimpressed with the display, Allura reaffirms she must portray strength as a leader to hide her doubts, and asks the mice to keep things a secret. The mice inform her of some secrets they know about the Paladins by performing a rendition of each - one of which is something about Pidge that leaves Allura in disbelief and seeking to investigate the matter herself.
At the party, Lance and Hunk discuss the reality of their situation. Lance wonders if they should get used to "space juice" since it is uncertain when they will return to Earth. Hunk thinks they likely never will return, since they have 10,000 years worth of conquered planets to free, an empire to destroy, and a universe to fix - if the Paladins even survive the beginning war. Lance is bothered by the concept but reluctantly agrees. Hunk considers the possibility of a nacho planet and this prompts Lance to reflect on things he enjoyed on Earth, as well as the family he left behind. The memories invoke tears to his eyes and Lance has to excuse himself by claiming the Nunvill is responsible. While Hunk watches in confusion, Coran also notices Lance tearfully leave the vestibule.
The Detective Princess
Allura approaches Pidge and asks about the Green Paladin under the guise that they have not conversed much. She is only given trivial information about Pidge's preference for peanut products and disdain for peanuts themselves, as well as how Pidge sweats a lot. Allura presses for more personal information and claims they have a lot in common. When asked how, Allura struggles and says that they both lost their fathers to Zarkon. Pidge bluntly admits this is true, but unlike the fate of Alfor, intends to see the return of Samuel Holt alive. Realizing this dredges up painful memories for Allura, Pidge apologizes, but the princess forgives and says Pidge is welcome to talk to her about anything. At this, Pidge admits there is something that needs to be discussed, but it is not the secret spilled by the Altean Mice as Allura hopes: Pidge is leaving the team.
Flabbergasted, Allura listens as Pidge explains that the information decrypted from Sendak's warship gave some insight to where the missing Holt family members had once been, so Pidge intends to leave that night to search. Allura protests the decision, as Pidge is now a Paladin with the sacred trust to defend the universe. Pidge is angered, having thought Allura would understand the loss of family more than anyone, and asks the princess if she would take any chance given to her to have her father alive and well again. Allura is pained and unable to respond. Pidge apologizes, but remains firm in the decision and leaves to speak with Shiro outside the Castle of Lions.
Haxus is hiding among the rocks nearby as Pidge approaches Shiro. He uses a scanner to copy the signature code of Rover, Pidge's drone that is loyally following the Green Paladin. Shiro nearly spots him, but the Galra alien hides quickly enough to avoid detection and flees once he reconfigures the bomb drone to take on the appearance of Rover. Pidge leads Shiro back inside the Castle, both of them oblivious to the reconfigured bomb drone entering the open doorway behind them.
The Galra Strike
Where to Call Home
Coran finds Lance sitting forlornly in the Bridge of the Castle of Lions after following him when he witnessed the Blue Paladin tearfully leave the party. Lance does not mind the company, and asks the Altean how far away Earth is from Arus. Coran brings up a holographic map of the universe to compare the locations of the two planets; the vast expanse of distance prompts Lance to reflect on how far away objects in space are from each other. He points out how he cannot even see any part of Earth anymore aside from in his memories. Coran sympathizes with Lance's homesickness, having lost his home planet entirely. Although the stakes of their mission are high and he has the power as a Paladin to change the dire state of the universe, Lance admits he simply wants to go home. Coran agrees that he would return to Altea if possible. The two bond over reminiscing about their home planets.
Among the Castle's halls, the Galra bomb drone continues to search for its target. The rest of the team remains unaware as Pidge addresses them in the vestibule and announces the decision to leave Team Voltron to search for the missing Holt family members alone. Keith protests the very thought of it, angered that Pidge would selfishly abandon the team and make them unable to form Voltron, therefore unable to combat Zarkon. He reminds Pidge that the missing Holts are not the only family in the universe: everyone has families. Hunk interjects that he also has a family, back on Earth, and that he would like to be with them.
The situation triggers a rage in Keith rarely seen before, and he aggressively closes in on Pidge, thinking it beyond absurd that the Green Paladin would value the lives of two people over the lives of everyone else in the entire universe. Shiro grabs Keith by the arm and reminds the Red Paladin that no one can be forced into being a team because people must want to be part of one. Keith silently relents; Shiro says they will not interfere, but asks Pidge to seriously consider what leaving the team will entail. Pidge remains steadfast in the decision and leaves for the flight pod with Rover. With no one to pilot the Green Lion, Allura laments their inability to form Voltron now that the team has so quickly collapsed.
The Galra bomb drone enters the Bridge and heads directly to the Castleship's Power Crystal as Coran and Lance are returning to the party. Lance initially mistakes the drone for Rover and greets it, but quickly realizes the drone is not what he thinks because it ignores him and Pidge is nowhere in sight. As the Galra drone prepares to detonate, Lance launches himself at Coran to shield him from the explosion with his own body. The massive blast is felt throughout the entire Castle and sends the Arusians into a panic, fleeing to their village as the rest of the team gathers in the Bridge.
Shaken but mostly unharmed, Coran is unable to tell anyone what happened. As the smoke and debris clear, Allura sees the Power Crystal for the Castle of Lions has been destroyed, and finds Lance unconscious on the floor. Shiro holds him and tries in vain to wake him; Pidge suggests taking the Blue Paladin to a healing pod in the Sleep Chamber immediately, but it is a fruitless idea because now that the Crystal is destroyed, the Castle is without any power, so none of the pods can heal him. The Arusian King suddenly enters in a fright with claims that the Arusian village is under attack. The Paladins cannot access their Lions to assist because the hangars are locked with no power to open them. The Castle of Lions has been utterly crippled and rendered defenseless.
Coran gathers himself and decides they must seek out a new Crystal to power the Castle. That means they need a ship, and Pidge remembers the flight pod prepared earlier to start the search for the missing Holt family members - the bay door was left open, allowing it to take flight. Coran believes the flight pod's scanner can locate a Balmera nearby, the source of the type of Crystal they need. He asks Hunk to accompany him as he will need someone strong enough to help carry the massive Crystal once they find one. Pidge takes Hunk and Coran to the flight pod.
Keith decides he will investigate the attack on the Arusian village and Allura, believing this incident is her fault, chooses to accompany him along with the Arusian King. Shiro tells them he will watch over Lance and the Castle, so the team splits for the time being.
In the flight pod hangar, Coran is able to locate a Balmera close enough to not require a Wormhole. Pidge informs the two team members of the modifications given to the pod: a cloaking device Pidge reverse-engineered from the Training Deck's invisible maze, and a tank of booster fuel mounted to the fuel line. Coran exclaims that using something like that during flight would turn the pod into a bomb, which leads Hunk to panic. Pidge agrees that using the technology should be avoided.
The Castle Taken
Shiro vs. Sendak
As he heads for the Castle doors, Shiro carries Lance, who remains unconscious, over his shoulder. He is alarmed to see Sendak approaching with a small squadron of Galra Sentries carrying a Galra Power Crystal and recognizes the commander right away. Shiro carefully lays Lance down so he can rush to meet Sendak at the entrance and prevent him from gaining access to the Castle of Lions.
Sendak orders Shiro to stand aside; Shiro refuses, stating Sendak will not be allowed in, and activates his prosthetic arm. Sendak affirms that he will gain access and attacks Shiro with his own massive prosthetic arm: a clawed gauntlet that can launch from his body while remaining attached at his shoulder by an energy chain. The gauntlet grabs Shiro and drags him across the ground, nearly smashing him afterward. Shiro dodges and furiously battles the Galra commander. His arm is unable to cut through the metal of the large gauntlet, but Shiro's agility saves himself from several attacks. The two warriors each throw a punch that cancels out the other, leaving them locked at the knuckle.
Sendak remarks how Shiro must have been experimented on by the Galra Druids, yet did not receive the latest model of their exploits. Shiro, exhausted, is unable to avoid the gauntlet as it launches forward and sends him flying back inside the Castle of Lions, directly beside Lance. The clawed gauntlet smashes down and Shiro scrambles to escape; Sendak uses his gauntlet to pull himself into the air to strike but Shiro uses the weight and propulsion against him, grabbing the Commander and tossing him across the Castle's vestibule. Shiro rushes to attack as Sendak scrambles to recover, and the two warriors freeze with each other's glowing hands poised dangerously against their throats.
Unfortunately, Shiro had been so caught up in the battle that he left Lance unguarded. Haxus orders Shiro to free Sendak and stand down or Lance, still unconscious, will be killed. The distraction of the decision gives Sendak an opportunity to strike Shiro unconscious. Sendak declares victory and heads for the Bridge as the Sentries gather the fallen Paladins. The Galra commander is unaware that Pidge is still inside the Castle of Lions and witnessed the fight.
The Castle Falls
Keith and Allura arrive at the burning Arusian village with the Arusian King. Massive explosions are ransacking the village, and the Arusian King points to Galra Sentries standing among the flames. Keith fearlessly dives in to the fray for a closer look and sneaks through the fire to approach the Sentries. To his shock, the Sentries are broken ones posed as decoys to lure the team outside of the Castle of Lions and thin their defenses. Keith relays the alarming news to Allura through her communication earrings and they rush back towards the Castle.
Inside the Castle Bridge, the Galra hook up their own Power Crystal to the Castle of Lions, causing the lights of the Castle to ignite but in the standard Galra violet as opposed to the natural Altean blue. Pleased to find the Voltron Lions remaining helpless in their hangars, Sendak orders the particle barrier as well as the launch sequence activated. A dark barrier overtakes the Castleship just as Keith and Allura arrive on foot, barring them from entering at the last second. Keith angrily slams his fist on the barrier to no avail; Allura is horrified the Galra are taking Voltron.
Sendak, meanwhile, speaks to Zarkon through a video transmission and explains their apparent victory. Zarkon is pleased with his commander and awaits the Lions. With the Galra preparing for takeoff, all seems lost with Shiro and Lance unconscious and Keith unable to break through the particle barrier with his Bayard. Allura is aware that whoever is inside has a Crystal to power the Castleship, so they must be stopped before they launch. Just as Keith wonders how that will be possible in their situation, Pidge contacts him through his Paladin helmet, informing them that the Green Paladin is still inside the Castle and that Lance and Shiro have become prisoners of Sendak, who is preparing to launch the Castleship into space.
Allura informs Pidge that there is little time before the launch sequence completes, but it is possible to force Sendak to reset the sequence if Pidge is able to access the main engine control panel and disconnect part of it from the Central Energy Chamber. This might buy them more time to come up with a plan to stop the Galra from taking Voltron. Pidge begins undertaking the task.
A Living Planet
Meanwhile, Hunk and Coran reach the nearby Balmera in the flight pod. The royal advisor informs Hunk that the Balmera is not a true planet. Rather, it is an ancient petrified, yet living creature that produces Crystals used to power various spacecraft. Coran reflects on how he visited many Balmera while his grandfather was building the Castle of Lions in the past, and how awed he was at the sight of a Balmera's sparkling surface, thinking them majestic creatures to be revered. To illustrate, he brings up an image of a sparkling Balmera on screen. Much to his horror, the state of the Balmera they have found is nothing like what he remembers: the creature is barren and riddled with holes because it has been turned into a mining colony for the Galra Empire, which holds no regard for its health.
Coran is absolutely appalled and angered at the state of the poor creature, but has no time to act on it. A massive Galra battle patrol jet detects them and demands they identify themselves and where they intend to land. Hunk begins panicking; Coran attempts to alleviate the problem by radioing to the patrol in a passive voice that they are simply looking around. The Galra battle patrol orders them to land and prepare to be boarded. Coran meekly agrees to their order. It is a ruse: he reverses the flight pod backward in an instant, spins into proper position, and takes off to escape the patrol jet at high speed, causing Hunk to scream.
The Galra battle patrol fires lasers at the flight pod and Coran sends the flight pod into a nosedive down a dark mining hole to escape the assault. Hunk continues to scream at the royal advisor's crazy piloting until the lack of anything occurring for several moments saps his motivation to scream. After stopping, he calmly questions how deep the hole they entered is. Suddenly, the flight pod collides with a Galra structure and spins into a fall, making both of them scream in earnest as the flight pod crash-lands at bottom of the hole.
The bottom of the mine is eerily silent as the windshield of their flight pod dissipates and Hunk looks around them. In the darkness of the mines, he sees two pairs of glowing eyes staring back from the black abyss. Hunk apprehensively asks Coran what lives in these mines.
The Last Paladin
Back on Arus, Pidge is making way through the Castle of Lions with Rover following along. Sendak is oblivious to the infiltration, believing the remaining free Paladins are trapped outside the Castle. The Galra prepare to launch. Pidge reaches the Central Energy Chamber and asks Allura what needs to be done since the engine turbine appears to have started. Allura instructs Pidge through their communication channel to open the control panel and is about to list off a sequence to be inputted, but Pidge has to pause her because the labels of the technology are in unreadable Altean. There is no time: the launch begins, causing massive energy to swell the Chamber and disrupt the communication channel.
Allura and Keith helplessly watch the impending launch as Sendak embraces his victory. Pidge, scrambling to find a quick solution, throws all caution to the wind and simply summons the Green Bayard to jam it into the engine turbine. The violent reaction throws Pidge across the Chamber, but successfully interrupts the launch and shorts out the engine. Pidge celebrates the success with Rover. The Galra are baffled by this development. However, Sendak spies Pidge fleeing from the Central Energy Chamber on screen and orders Haxus to eliminate the Green Paladin.
- This episode title is listed as "Fall of the Castle of Lions" on Netflix, excluding the first "The" seen in the episode title card.