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

1-8
: 1L+2L set, cross passing partner RSh & chase clockwise to own sides to
  change places similarly 3L+4L dance likewise
9-16
: 1M+2M set, cross passing partner LSh & chase anticlockwise to own sides
  to change places **while** 3M+4M dance likewise
17-20
: 2s+1s also 4s+3s dance LH across
21-22
: 1M+4M change places RH
23-24
: 1L+4L change places LH
25-32
: All dance RSh reels of 4 on sides (1s+4s pass RSh at end)