Blossom and Dexter were in the libary studying. Dexter left and went to his secret lab inside the school, but was followed by Blossom. When she was inside of the lab she saw a dead girl haning in the lab and first mistaked her for Bubbles but when she looked closely she saw it wasn't her. Dexter came and told her she shouldn't be here and kicked her out of his lab. When Gumball came to Blossom searched for Otto and told him what she saw in Dexter's lab. Otto told her that it was just an android but also an except replica of Dexter's older sister Dee Dee. He took Blossom and Gumball with him through time to let her show the past of Dexter. Otto told her that Dee Dee was very annoying and constantly destoryed Dexter's lab. But that was just a normal brother-sister relation. Dee Dee also took Dexter sometimes with her to talk about nature. Once of those times Dee Dee said to Dexter that if she dies that he shouldn't try to bring her back. Then on another day when Dee Dee sneaked inside of Dexter's lab Mandark broke in along with his robots. They began to battle until one of the robots fired a laser towards Dexter and Dee Dee tried to save Dexter by jumping in front of it. When that happened Dee Dee was dead and Mandark retreat, much to the horror of Blossom and Gumball is feeling sad. There was a funeral for Dee Dee and her Mom and Dad came so as her two best Friends Lee Lee and Mee Mee, while Dee Dee was watching. Dexter couldn't accept that his sister was dead and began to make an android of her. But he wanted to make that android as human as possible so he used real human organs in the android. Suddenly Dexter heared voices of Dee Dee about the promise they made. Dexter quickly fleed and went to her grave where also Mandark was (who also was in love with Dee Dee). When he saw him Dexter pulled his knife and tried to kill Madark for what he had done to Dee Dee. When she and Gumball arrive was back in the normal time she encountered her sister and huged them, Buttercup reacted angry and reacted it towards Otto. When Blossom was gone outside and sat at a tree and Gumball arrive feels when suddenly she was encountered by Bell and Mojo, who began to fight with her.