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

1-8
: 1s dance down middle as 4s dance up & set to partners, 1s dance up &
  cast to 2nd places as 4s dance down & cast up
9-16
: 2s+1s also 4s+3s dance Diamond Poussette
17-24
: 1s & 4s dance 1/2 Fig of 8 round 2s/3s, 1L+4M also 1M+4L turn RH 1.1/2
  times
25-32
: 2s+4s+1s+3s Adv+Ret, all turn partners RH