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

1-8
: 1s dance down to meet 4s who dance up, set to partners, 1s lead up &
  cast to 2nd place as 4s lead down & cast up to 3rd place
9-14
: 1s in prom hold dance reel of 3 on Ladies side (giving RSh to 2L to
  start) **while** 4s dance reel on Men's side (giving RSh to 3L)
15-16
: 1s+4s dance LSh round each other to face corners (4s face 2s & 1s
  face 3s Men to Men & Lady to Lady)
17-24
: 1s+4s dance 1/2 interlocking diagonal reels of 4 with corners to end on
  sides 3 1 4 2, 3s+1s & 4s+2s circle 4H round to left open into-
25-32
: All circle 8H round & back