After Ruby reveals that the Red and Blue Jewels are inside of his and Sapphire's bodies, Juan looks down, resigned, and asks why he thinks that. Ruby pulls out the diary that Plusle and Minun have been guarding. Ruby explains that he realized the author of the diary was the inventor of the scanner, and since the scanner was made to detect the Blue and Red Jewels, Ruby thought the diary was probably important. Reading it, he found that the Jewels need "controllers" (or hosts) to maximize their power. The diary said that the Jewels can even choose their controllers.