After all teams have performed and seven top-scoring contestants have been selected, it's revealed that the top fifteen overall best-performing contestants will be ranked and placed in the upper tier. In the next mission, the fifteen Upper contestants have the opportunity to choose a contestant among the lower-ranked contestants to partner with, beginning with the first-ranked contestant. The partners' scores will be combined and the teams will have the opportunity to choose their next song in the order of their newly combined rank. Of course, with thirty-five contestants, this leaves five unpartnered contestants behind. (Source: MyDramaList)