1-8
: 1s turn RH & LH
9-16
: 1s lead down to just below 3rd place, 1M leaves partner in 3L's place &
  leads 3L up to 1L's place
17-24
: 1M+3L turn RH & LH **while** 3M+1L do likewise
25-32
: 1M leads 3L down to just below 3L's place & leads partner up to top
  place & both cast to 2nd place own side