1-8
: 1s+2s also 3s+4s dance RH across, 1s cast 2 places **while** 2s+3s dance
  up
9-16
: 2s+3s also 1s+4s dance LH across, 1s dance up to top as 2s+3s step down
17-24
: 1s cross RH, cast 1 place, cross RH & cast to bottom ending with 2s
  facing 1s up/down centre
25-32
: 2s & 1s advance towards each other & retire, 1s also 2s turn 3s/4s with
  nearer hand to end 2 3 4 1