1-8
: 1s lead down middle & up then cast 1 place
9-16
: 2s+1s+3s Adv+Ret, 1s cross RH & cast round 1st corner into lines of 3
  across
17-24
: All Adv+Ret, 1s change places LH & cast left to 2nd place own sides
25-32
: 2s+1s dance R&Ls