From facing lines: Working as couples those on the right end of each line (with inside persons acting as pivots) wheel left about a quarter into the center where the original ends meet as centers of a two faced line. Turn the line about another quarter and step forward as couples (to be the left hand couple facing out in the other line). When the right hand couples clear the center, the left hand couples do the same thing to cross through the middle and become right hand couples facing out in the other line. Finishes with two lines facing out.
COMMENT: The term Zig Zag has acquired a meaning different from the one used here; i.e., from a single file of two, lead person does a quarter right and trailing person does a quarter left.