Trama

Steven thinks his time defending the Earth is over, but when a new threat comes to Beach City, Steven faces his biggest challenge yet.

Two years have passed since Steven Universe resolved the ongoing conflict between Earth and the Diamonds and brought peace to the galaxy, seemingly allowing Steven and the Crystal Gems to live happily ever after. However, Steven's past comes back to haunt him in the shape of a mysterious Gem hellbent on destroying him and everything he holds dear, including the Earth itself. Steven must now face the consequences of Pink Diamond's actions, save the Earth and, once again, go on a path of self discovery and change to truly earn his happily ever after.—George Allen

After an introduction from the Diamonds ("The Tale of Steven") (Diamonds rules the Gems world. gems ruled many planets, but the Pink Diamond only ruled Earth. She left home to settle on Earth and give birth to mankind via Steven. Without Pink, the Gems world fell into despair and war. But Steven learned his legacy and restored balance).

Steven Universe (Zach Callison) (now 16 years old) (a Gem-human hybrid member of the Crystal Gems and former member The Great Diamond Authority) greets the citizens of the reformed Gem Empire. The Diamonds (Blue, white and Yellow) want him to stay to fulfill his mother Pink Diamond's role as leader ("Let Us Adore You"), but he refuses (The Diamonds are not happy that Steven doesn't want to stay on the gems world). Back on Earth, Steven, Pearl (Deedee Magno Hall), Garnet (Estelle Swaray), and Amethyst (Michaela Dietz) celebrate their newfound "Happily Ever After". Almost immediately afterwards, a giant drill lands on the hillside of Beach City and Spinel, a deranged and cartoon like Gem, appears, announcing her intent to kill Steven and the rest of the Earth ("Other Friends"). Using a scythe-like weapon, she "poofs" Pearl, Garnet, and Amethyst back into their gem forms; her attacks also weaken Steven's Gem powers, though his body is unharmed. Steven manages to poof Spinel (Sarah Stiles) (the former playmate of Pink Diamond, Steven's late mother) with her own scythe.

Steven calls his father, Greg (Tom Scharpling), for help. The Gems regenerate their bodies (including Ruby (Charlyne Yi) and Sapphire (Erica Luttrell) separately as Garnet was a fusion of the two), but their memories have been erased; Pearl assumes that she is Greg's servant. With her memories gone, Spinel is a goofy and happy-go-lucky Gem whose function is to entertain her companion. Steven seeks advice from Peridot (Shelby Rabara), Lapis Lazuli (Jennifer Paz) (a member of the Crystal Gems who was formerly aligned with Homeworld), and Bismuth (Uzo Aduba); they encourage Steven not to give up ("Who We Are"). Spinel compares the situation to a puzzle, suggesting that they find the Gems' "missing pieces" to restore their memories, inspiring Steven to try to reenact Ruby and Sapphire's first fusion. Spinel's antics cause scaffolding to collapse, almost crushing Ruby; when Sapphire shoves her to safety, they fuse into Garnet ("Isn't It Love?"), but she still has no memory of her life.

After Steven recovers Amethyst's memory by reenacting experiences the two had together ("No Matter What"), Peridot discovers that Spinel's drill is injecting a toxic chemical that will kill all organic life on Earth. Steven's attempts to remove the injector only accelerate the poison's effects. The group thinks that restoring Spinel's memory might help as she might know how to deactivate the drill. But Steven can't bring her back, as he doesn't know her. The only person who knew Spinel was Pearl. In order to revive Pearl's memory, the group takes her to a Sadie Miller (Kate Micucci) and the Suspects concert, in the hope their music will bring back her memories of rebellion ("Disobedient"), but Pearl insists that as long as Greg exists, she will obey him. Steven uses what little energy he has left to fuse with Greg ("Independent Together"), which enables Pearl to recover her memory. She tells Steven that Spinel was once Pink Diamond's playmate; Spinel is suddenly overcome with sadness and flees.

After sending for Connie (Grace Rolek), Steven finds Spinel crying at his house. She takes Steven to a desolate garden in space and reveals her backstory: when Pink Diamond went to begin the Gem colonization of Earth, she told Spinel to wait for her in the garden on that world (which was green and beautiful at the time); Spinel was left there alone for 6,000 years until she learned of Pink Diamond's fate ("Drift Away"). Steven tells her that he will never abandon her and that he will make up for his mother's mistakes ("Found").

Back in Beach City, Spinel turns off the injector, but when Steven begins shifting his attention back to everyone else, she accuses Steven of just using her and then abandoning her or planning to wipe her memory again. She turns the injector back on and attacks Steven. As he tries to explain the truth to her, Garnet recovers her memory. Steven sends the others out to rescue the humans of Beach City while he confronts Spinel ("True Kinda Love").

Steven finally realizes why his Gem powers have not yet returned: his desire for an unchanging "happily ever after" has left him resistant to the very notion of growth and change, which he needs to re-experience. Embracing this fact, he regains his powers and battles Spinel, trying to convince her that she can change as well ("Change"). Their fight destroys the injector, and Spinel relents after realizing how much she hates what she has become.

The Diamonds suddenly arrive, intending to live on Earth with Steven. He introduces Spinel to them, and they take an immediate liking to her and her goofy personality ("Let Us Adore You (Reprise)"). The Diamonds accept her in place of Steven, and she happily goes with them, now with people who will love her unconditionally. Steven and his friends gather to rebuild Beach City. Steven, Connie, Pearl, Garnet, Amethyst, and Greg perform a Broadway-style "Finale".