The Sixth Key is the thirteenth episode & the season finale in the second season of the Final Space series. It aired on September 23, 2019 on Adult Swim and September 30, 2019 on TBS.
With the dimensional keys recovered, the crew travels to Inner Space where they finally try to free Bolo.
With the five keys in their posession, the Team Squad is on its way to Sector 12, region 6, where the entrance to Inner Space is. But the main question is; should they free Bolo? Gary is unsure, and doesn’t want to make another mistake. Little Cato advises him something Avocato always said; find the least trustworthy person, and to the exact opposite from what they do. Then Sheryl suddenly enters the room and points a gun at Gary. Tribore let her out of her cell after she complimented him on his fashion. She again claims Bolo is evil, and that she won’t let Gary stop her from seeing John again. Fox knocks her out before she can hurt Gary. Gary orders Tribore to lock her up again.
The Crimson Light arrives at the sun in the Orion Nebula, but there is a level 9 solar storm raging. ary won’t wait however, and prepares to once again lightfold into the aperture that will send them to Inner Space. But the solar storm isn’t the only problem. Another ship approaches the Crimson Light and opens fire. Little Cato volunteers to man the turret pod (which is next to the bowling alley, which Gary didn’t even know they had) and take care of the attacker. The other pilot easily dodges the shots as both ships maneuver between the solar flares. Then Little Cato notices the other ship’s pilot is none other than Avocato, still possessed by Invictus.
At the brig, Tribore claims they need Sheryl’s help. She could be a valuable asset in the upcoming fight with the Titans. He is convinced he can get her and Gary to make amends, using deep, deep, deep, deep, deep brain-ial therapy. And a virtulazium. He has Sheryl taken to the Virtulazium, and has H.U.E. give her a hyper-link bypass into her cerebral cortex. The Virtulazium recreates the day John broke up with Sheryl. And she grew to hate Gary. Meanwhile, after several tries, Little Cato finally gets a lock on Avocato’s ship, and with great reluctance, he takes the shot. Avocato’s ship is disabled, allowing Gary to finally lightfold into a apperture. He pulls it off again, and the Crimsion Light arrives in Inner Space. The Crimson Light however has sustained quite some damage. The lightfold engine, drop drive and video arcade (again, a room Gary didn’t know they had) are all offline.
Gary asks Little Cato to fix the engines, while he, Nightfall and Mooncake go to talk with Bolo. When Gary asks Bolo about Oreskis, he reveals that he was once in a relationship with a female Titan named Jill before Invictus appeared, but she cheated on him with Oreskis and got infected with a Titan STD. This story convinces Gary to trust Bolo. To free him however, they need Mooncake, and a sixth key; a sacrifice. In the virtulazium, Tribore calls Sheryl out for blaming Gary for everything. He was after all the product of her and John’s love. To make his point clear, he shows her the life she could have had if she and John never broke up. Or even if she had simply stayed around. Sheryl begins to feel regret, but claims it’s too late now. H.U.E. points out she can make new memories. John is gone, but she still has Gary. Sheryl breaks out of her cuffs, and accepts Tribore’s offer to join them.
Gary is not pleased that Bolo never told them someone has to be sacrificed to free him. Bolo justifies his actions with the fact that Gary wouldn’t have come back had he known this sooner. It is the only way and if they don’t free him, Quinn will die. Gary nominates KVN to be the sacrifice, but alas; as a robot, KVN does not qualify as life. Then Avocato suddenly shows up, having made his way to Inner Space as well. He attacks Gary, and knocks him off the Crimson Light, onto Bolo’s prison. The whole Team Squad, including Sheryl, comes to Gary’s aid, but due to Invictus, Avocato is simply too strong and takes them all out.
Nightfall urges Mooncake to free Bolo while Invictus is still distracted. She will be the sixth key. Mooncake doesn’t want to kill a friend, but Nightfall insists; hopefully this way, there will be at least one universe in which Gary and Quinn end up together. The keys line up, while Mooncake charges his beam. Gary pleads for Nightfall not to go through with this, to no avail. Mooncake blasts the keys, and Nightfall. Bolo’s prison begins to break apart, as Nightfall dies. Seeing Nightfall die sends Ash into an unstoppable rage. She unleashes her full power on Avocato, and drives Invictus out of him.
Bolo is freed. Gary mourns the loss of Nightfall. Bolo assures him her sacrifice will not be in vain. Avocato is himself again, though he is naturally confused about what happened. Now that Bolo is free, Inner Space begins to fall apart. Bolo orders the Team Squad to return to their ship. The Lightfold Engines are still offline however, so A.V.A. can’t take them out of Inner Space. Sheryl claims it's a good thing they have her; the best pilot in the universe. She makes it clear she will be there for Gary from now on. Little Cato will try to fix the engines again. He is so happy both of his dads are with him now.
As Inner Space collapses, The Crimson Light speeds for the exit, with Bolo close behind. When Gary has trouble dodging the debris of Inner Space, Sheryl takes over the controls. Although she does a better job than Gary at flying the ship, they still won't make it in time. So Bolo grabs the ship and throws it towards the exit. It works; the Crimson Light re-emerges from the sun, and so does Bolo. Bolo calls the Arachnitects. He asks them to send him and the Team Squad to Final Space to take on the Titans. And Invictus. The Arachnitects remind him that the fate of the whole univere is at stake, and that it will be a one-way trip since they will seal the entrance behind them. The Team Squad is ready however.
Bolo and the Crimson Light enter Final Space, and emerge right where Quinn is. Gary immediately leaves the ship to get to her. The two lovers are reunited at last, but the fight has just begun. Invictus is awaiting them.
- Olan Rogers as Gary, Mooncake and Tribore
- Tika Sumpter as Nightfall and Quinn
- Keith David as Bolo
- Steven Yeun as Little Cato
- Coty Galloway as Avocato
- Claudia Black as Sheryl
- Ashly Burch as Ash Graven
- Fred Armisen as KVN
- Tom Kenny as H.U.E.
- Jane Lynch as A.V.A.
- Ron Funches as Fox
- On its premiere on Adult Swim, it was watched by 639.000 viewers and it was the highest watched animated program of the night.
- Highest rated episode on IMDB so far, with 9.6/10.
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