1-4
: 1s+2s also 3s+4s set & dance RH across 1/2 way.  2 (1) 4 (3)
5-8
: 2s&4s dance 1/2 fig of 8 down round 1s&3s
9-16
: 2s+1s dance Ladies' chain **while** 4s+3s dance Men's chain
17-24
: 1s+3s Petronella turn to face up/down & set to partner, repeat to finish
  on own sides in 2nd/4th places.  2 1 4 3
25-28
: 1s+3s dance 1/2 R&L **while** 2s+4s set to partners & cross RH
29-32
: All set & cross RH.  2 3 4 1