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

1-4
: 1s & 4s turn 2H & remain in middle as 2s & 3s step down/up into lines
  across & all set 1s+4s advancing to pass partner LSh to face 2s/3s
5-8
: 1s+2s also 3s+4s dance 1/2 reels of 4 across & 1s+4s end 1/2 turning
  partner LH to face up/down LH to partner & RH to 2s/3s
9-16
: All Bal-in-Line twice, 1M & 4M turn left about & lead LH partners out
  ends of set crossing & casting to 2nd/3rd places. (2)(1)4 3
17-20
: 1s+4s turn 2H on sides & all set (2s+1s facing down, 4s+3s up) with
  1s+4s advancing to pass LSh on sides to face 2s/3s
21-24
: All dance 1/2 reels of 4 on sides & 1s+4s end 1/2 turning LH to face
  across giving other partner LH & RH to 3s/2s. 3(1)4(2)
25-32
: All Bal-in-Line twice, 1M+4L also 1L+4M change places LH & then chase
  anticlockwise 1/2 way. 3 1(4)(2)