1-8
: 1M+3L cast 2 places (1M down, 3L up), meet in centre & turn LH to finish
  in each other's place
9-16
: 1L+3M repeat but turning RH
17-32
: 2M+4L repeat turning LH, then 2L+4M repeat turning RH
33-40
: 3s+4s & 1s+2s dance 1/2 R&L, 1s turn RH **while** 4s+3s+2s dance 1/2
  reels of 3 on sides