Lance is apart of Blue Diamond's ( Haggar) court, while Keith is under Pink Diamond ( Allura ). They're both under their respective Diamond's protection. Lance is visiting Blue's kingdom down on Earth, and Keith - along with several other ruby guards - is sent as protection. Sapphires are precious gems, after all. Upon meeting, the two don't particularly get along. Lance doesn't think he needs protection; and Keith would rather be anywhere else but on Earth. On the way to give Blue Diamond a prediction on how the War will end, the two gems argue until they accidentally fuse. In front of an entire gem court. This causes an outrage, and the two are forced to flee.