Head couples do a right and left thru, then veer left to form a two-faced line. This two-faced line now turns in the center. When the No. 1 couple is opposite the number 2 couple, the center ladies chain with the outside ladies to be courtesy turned by the side men. (The outside ladies coming into the center will be scooped up by the next man coming around in the center of the two faced line--not the man who had as a partner the girl she originally chained with). The two faced line continues to turn and the No. 1 man scoops up the #4 lady, takes her around to the #2 side and chains her out there, then moves around to scoop up the #3 lady from the #4 side and then turns far enough so he and the other head man can back out at home positions. All now have opposite ladies. Have the sides go in to repeat the above sequence and all finish with partners at home position.
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.