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

1-8
: 1s set adv. & turn 2H to face down & give nearer hand to 2s (2s face
  up), 1s+2s set & 1s turn 2s on sides with nearer hand to finish in
  lines across facing down, WHILST, 4s dance likewise with 3s
9-10
: All set
11-16
: 1s & 4s change places RH, cast behind 2s & 3s, pass partner by the right
  to face corner (4M facing 2M, 4L facing 2L, 1L facing 3L, 1M
  facing 3M) on the diagonal
17-24
: All dance (RSH) interlocking diagonal reels of 4 to end on the sides 2 4
  (1) (3)
25-32
: 4s & 1s, giving RSH to corners, reel of 4 on sides, middles passing RSH
  at end 2 4 (1) (3)