A1 – 1st Couple cast off below the 2nd Couple and lead up the middle.
A2 – 2nd Couple cast up and lead down the middle.
B – 1st Man change places with the 2nd Woman, falling back the last 3 steps. 2nd Man do the same with the 1st Woman. All take hands and go halfway round, the 1st Couple then casting off into the 2nd Couple’s place.
Repeat down the line, the rest doing the like.