Yukio falls, and the Mother takes Rita. Whatever happens after that doesn't seem to matter much to Rin, who rushes to his fallen twin. He takes the sleeping-gun, just in case the Mother decides to take him again, and he holds Yukio in his lap, fretting and worrying.

“Yukio! Yukio, can you hear me…?”

Either way, if Rita gets rescued, Rin has Yukio contained.