{{explanation}}
2 Ch - 1M & 3M stand as 1L & 3L cross down to 2M/4M place who cross over to partners place as 2L/4L step up (Ladies on right of partners)

1-8
: 1M+2M also 3M+4M 3/4 turn RH & dance RSh round partner to places, 1L+2L
  also 3L+4L repeat LSh
9-16
: 1s+2s also 3s+4s set & circle 4H round to left 1/2 way, set &
  petronella-in-tandem. (1)2(3)4
17-24
: 1s & 4s Set+Link twice & end on sides **while** 2s+3s Set+Link with
  partner rotating to face partner then Set & Rotate with other prtnr to
  end (1)3(2)4
25-32
: 3s & 1s dance out between end cpls & cast back to place, all set & Men
  cast 1 pl clockwise as Ladies cross to end 3s+4s M side & 1s+3s L side