Steven walked in on Ruby and Sapphire talking to the gem, still not formed, 

"Come on Emerald!" Ruby sat waiting, and Steven wondered over to them, "who really is this Emerald?" He asked sitting down.

Sapphire turned to him and smiled, "Emerald is a crystal gem" Steven sighed, "no, what is she like?" Right after Steven asked that Ruby replayed "everything," Steven sighed once more, "I'm going to go find amethyst" he get up, and wondered to Amethysts room, 

maybe she will know.

Steven walked over to Amethyst's room, and called for her "AMETHYST!?"  moments later she walked out "sup Steven" he smiled "hi Amethyst, I have a question" she looked at him, "okay sure, lay it on me" he smiled and took a deeeeep breath,

"soifoundthisgemonthebeach, andwhenGarnetsawitsheunfused, andbecameRubyandSapphire, andtookitinside, Pearlsaidthegemwasinthewarwiththem, andwaslost, BUTshewasreallyjustinarivercracked, andRubyandSapphirewonttellmeanythingexceptshe'sanEmerald, andshewasanassassin!" Steven wined

(what Steven really said: ~"so i found this gem on the beach, and when Garnet saw it she unfused, and became Ruby and Sapphire, and took it inside, Pearl said the gem was in the war with them, and was lost, BUT she was really just in a river cracked, and Ruby and Sapphire wont tell me anything except she's an Emerald, and she was an assassin!"~)

"wooooow Steven calm down! i'm not sure who this 'Emerald' is ether!" Amethyst said as the two wondered into the living room, Ruby and Sapphire looked up, Amethyst looked surprised,

"wow... you weren't kidding" Amethyst said, and Steven nodded with a smug look on his face, "oh boy..."