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

1-4
: 1s+2s also 3s+4s dance RH across;
5-8
: 1s cross down to 2nd place opp sides **while** 2s cast up, 3s cast down
  1 place & 4s cross up to 3rd place own side; 1s & 4s dance up/down
  behind 2s/3s
9-16
: 1s in prom hold dance a reel of 3 across with 2s (RSh to 2M to
  start) **while** 4s in prom hold dance reel of 3 across with 3s (RSh
  to 3M to start)
17-24
: 1s+4s (prom hold) dance clockwise round each other & dance out ends (1s
  up between 2s, 4s down between 3s) & cast to 2nd/3rd places
25-32
: 1s+4s dance 1/2 R&L (no polite turns) & all 4 couples turn partners 2H.
  2 4(1)(3)