{{explanation}}
Square set plus 5M / 5W in middle face P with backs to 4c / 2c

1–
: 1c+2c+3c+4c circle8 and back **while**{8} 5c turn RH ; turn LH 1½
9–
: 5M+2c & 5W+4c RHA ; 5M+1c & 5W+3c LHA
17–
: 1c+5M+2c & 3c+5W+4c (couples in promhold) Reels3 Rsh to side couple, 5c meets (5M swivels L) and takes promhold facing 1c
25–
: (all C promhold) 5c+1c change places Rsh | 1c+4c repeat ; 4c+3c repeat | 3c+2c repeat, 2c is the new centre couple.