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

1-8
: 1s+2s also 3s+4s dance 1/2 R&L, 1s+4s advance & 1/2 turn RH into prom
  hold to face out (1s facing Ladies' side & 4s facing Men's
  side) **while** 2s & 3s cross RH & set to partner
9-16
: 1s & 4s dance RSh reels of 3 on sides (1s RSh to 3M & 4s RSh to 2L) &
  end facing out
17-20
: 1s & 4s separate & cast to ends to meet other partner & face down/up
  (between end couples) **while** end couples (2s+3s) cross RH & set
21-24
: 1s+4s adv, turn ptnr 1.1/2 times to prom hold facing out side (as
  before) **while** 2s+3s turn RH 1.1/2 on sides
25-32
: 1s & 4s dance LSh reels of 3 on sides (1s LSh to 2L & 4s LSh to 3L) &
  end Men crossing partner over to other side. 2 4 (1)(3)