1-8
: 1s+2s+3s set, dance DoSiDo with partner & set
9-16
: 1s lead down for 4 steps followed by 2s+3s, change places with partner &
  lead up to order 3 2 1
17-24
: 3s giving RSh to 2s dance reels of 3 on opposite sides
25-32
: 2s+1s change places LH on sides, set to partner, 1s cross RH & set
33-40
: 1s dance Diag R&L to end 3 1 2 4

{{explanation}}
2nd time through ends 3 4 1 2, 1s step to bottom & 3s become new 1s