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

1-8
: 1s & 4s 1/2 turn partners RH to 2nd/3rd places (in centre) as 2s & 3s
  step up/down, 1s+4s set & cross up/down & cast to 2nd/3rd places.
   2 1(4)(3)
9-16
: 1M+4L also 1L+4M in prom hold dance 1/2 LSh reels of 3 on sides (up on L
  side & down M side), 1/2 RSh reels of 3 across with 2s/3s
  end 3 4(1)(2)
17-24
: 3s+4s also 1s+2s turn on sides (Men LH & Ladies RH), 1s & 4s dance 1/2
  Figs of 8 round 2s/3s
25-32
: 1s+4s dance Set & Rotate to end 3 1 (4) (2) :

: Set, rotate singly & dance on 1 place clockwise, change places RH on
  sides & dance on 1 place to own sides (1s in 2nd pl)