Beats 1-2: all dancers move into a single line with #1 facing down and all other dancers facing up.
Beats 3-16: Dancer #1 continues dancing more or less straight down the set. Dancer #2 continues, passing right shoulders with #1. All other dancers remain still until #1 approaches. As #1 approaches each dancer, the dancer starts dancing and veers off in the opposite direction from the previous dancer (passing #1 by the opposite shoulder from the previous dancer). Dancers continue through a linear hey until the set is inverted. I.e., dancer #1 stops at the bottom and turns to face up. Dancer #2 stops when facing #1. Each other dancers stops when they reach the back of a dancer facing away from them. The last dancer should stop on beat #16 (bar #8).
Beats 17-32 (bars 9-16): Repeat the above process except that #1 continues dancing off and the rest of the set follow.