(AN: this whole story is a AU from the episode mirror gem so the story will start there and the beginning will be slightly different too mirror gem)
Steven is having fun with the mirror he was given by pearl, they've been all round Beach city with the mirror showing what its seen to talk to Steven. its late at night and the mirror is making fart noises with Steven "your pretty funny for a mirror" Steven says, the mirror responds with the same thing and Steven laughs "i'm not a mirror" he says "your pretty funny for a STEVEN!" the mirror responds "You made something new! Say something else!" Steven says excitedly "Steven is my new friend" "really?" Steven says and the mirror responds with a replay saying yeah "your my friend too" Steven says and they both laugh "I got to go tell the gems" Steven says and the mirror starts screaming "don't be shy, they'll love you" but the mirror continues to scream "don't worry, there a good audience" the Mirror shows Steven scenes of gems fighting, some hiding in terror, the silhouettes looked like Garnet, pearl and his mom Rose Quartz plus a few he doesn't recognise. Steven is scared by what he just saw but continued to walk home.
Steven opens the door to see Pearl, Amethyst and Garnet, Amethyst and Pearl say hello to Steven at the same time "yo Steven" "hello Steven", Pearl is organising all the school equipment that she got out for Steven to be symmetrical, Garnet was a bit more entertaining "Howdy, bang". "Steven, wanna see something hilarious" Amethyst says while putting one of Stevens teddy bears on Pearl organised items. Pearl stabs the bear with her spear yelling at Amethyst for ruining her symmetry. Steven is slightly sad for the loss of Mc Bearbear, he quickly perks up to tell the gems what he did "I fixed the mirror!" Pearl congratulates him before Steven happily says "you didn't tell me it was like a person". The gems look shocked and confused at what Steven just said "say hey" Steven says showing the gems the mirror with a big grin. The mirror does nothing. The gems have the same reaction on their faces but probably also because their concerned about Steven and his imagination, "uh excuse us" Steven says "come on, you wanna come out dont you" the gems stay silent "you have so much to say and funny noises to share from across the ages. Are we not beach-summer-fun buddies?" The mirror is silent for a second before replaying Steven making a fart noise. Steven laughs "just couldn't help yourself, huh?" The mirror replays an earlier "just for you Steven" playing Steven laughing over and over again.
Pearl is concerned "It's talking to him? It shouldn't be able to do that. I-it should just be following orders..." "Garnet do something" Amethyst says. Garnet stands up and walks over to Steven, the mirror is still laughing until Garnet is looming over Steven where it replays Steven screaming. Garnets kneels down " You should just give us back the mirror. It will be safer where we can watch it" she says calmly. "yeah, let's bubble it!" Amethyst says very gung-ho. The mirror keeps screaming "Steven, don't make me have to take it from you" Garnet says puting her hand out. Steven starts backing up towards the door "It doesn't want to go with you. Don't you hear it screaming?" he says scared for his friend. "Steven, it's just a mirror, a tool. It can't want anything." Garnet says reaching for the mirror. The mirror keeps screaming as it sees Garnet reaching for her. Steven acts quickly "It wants to be with ME!" he says as he slaps Garnets hand, his slap causes her glasses to fall off, Amethyst gasp as Garnet stares at Steven with her three eyes. Steven panics and runs out the beach house screaming "im sorry" as hes halfway down the stairs.
Steven runs behind a rock on the beach "What am I gonna do? What's their problem with you?" he says panting heavily. The mirror starts to change what its showing "are you trying to say something?" Steven asks. "Away from home" the mirror says, its starts to show distorted images of the previous events to say what it wants "Let- Me- Out!" "I don't understand!" Steven says "STEVEN" Pearl scream in the distance. Steven starts panicking "come on! I want to help you! What can I do?" The mirror shows Steven new visuals, its of Steven pulling the water drop shaped gem off the back of the mirror and holding it up in the air. Steven acts on these instructions flipping the mirror and trying to pull the gem off, its harder then he imagined. The water of the ocean starts acting strange, it forms a circular shape around Steven just as hes able to pull the gem off. The mirror cracks and the gem starts glowing. The gem starts floating in front of Steven and forms into a blue gem. Steven walks up to the gem, she has a cracked gem on her back, she turns to look at Steven, she has mirrors for eyes "thank you" she says as she tries to stands up, Steven helps her as she nearly fall over "You actually talked to me. You helped me!" She says with a smile as she stands up "It's Steven, right?" Steven responds with a hmm and a slight nod "I'm Lapis - Lapis Lazuli. Are you really a Crystal Gem?" "yeah" he responds "but you set me free" Lapis says. Steven is confused by this before...
"STEVEN!" Garnet screams seeing him next to Lapis. The Crystal Gems get ready for a fight "WAIT" Steven yells running towards the gems not wanting anyone to fight "You..." Lapis says menacingly, she starts to form a large hand out of the water of the ocean behind her "you three knew I was in there, and you didn't do anything. Did you even wonder who I USED TO BE!" Lapis yells before she uses the hand to smack down on Garnet and pushing Amethyst and Pearl out of the way. "Steven run!" Pearl says. "What are you doing?" Steven asks Lapis. "I'm Lapis Lazuli and you cant keep me trapped here anymore!" she yells to the Crystal Gems still putting pressure on Garnet. Steven looks back at the gems "They're not going to let us leave" Lapis says "Leave?" Steven says confused. Lapis uses her powers to part the ocean in half "Steven, come with me." She tells him "where?" he asks" "home". Steven thinks to what hes seen just today and all the things he didnt know about the gems, they clearly have done some horrible things and probably more that he doesnt even know about. "STEVEN" Pearl screams. Steven looks back at her for a second, he turns to Lapis and runs through the parted sea with Lapis not far behind. "Steven" both Pearl and Amethyst yell. The water of the ocean closes behind Lapis as the two run as far as their legs can possible take them.