{{explanation}}
3s & 4s on opp sides

1-8
: 1s & 4s cross RH & cast in 1 place, 1s+4s dance LH across
9-16
: 1s & 4s change places RH with corners & 2s+3s dance LH across, all set
17-24
: All dance reels of 4 on sides
25-32
: All set, 1s+2s also 3s+4s dance RH across 1/2 way,  1s+4s dance LH
  across 1/2 way **while** 2s & 3s cross RH, all set.  2 4(1)(3)