Dance Notes by the deviser, Reuben Freemantle

The dance is intended to flow seamlessly from one figure to the next as far as possible so that, at the end of every phrase, the dancers are facing in the correct direction for the beginning of the next phrase.

  1-8   Partners should be exactly the width of the set apart at all times and on the same level up and down. Covering must be visual since hands cannot be taken in parallel reels.

    -8   2M3M 2L3L should already have passed left shoulders.

17-24 In reverse reels of 4 (also known as left shoulder reels of 4), the dancers pass by the left at the ends. The same considerations apply over parallelism as in bars 1-8.

23-24 Instead of passing right shoulders, 3M2M 3L2L take both hands and turn halfway by the right on the sides into original places (a quick movement similar to that in bars 31-32 of Fifty Years On); 4L finish facing out, all others in.

25-26 1s stand for two bars and so 1M can encroach on the beginning of this phrase to finish facing in.

    -32 On the 1st, 2nd and 3rd repeats, all release hands on the left foot step, pulling right shoulder back, 4M 1L 2M 3L turning 1⁄8 on the spot, 4L 1M 2L 3M turning 5⁄8.

(Dance Notes end)

This dance is so-named because 2s and 3s (like chaperons) successfully thwart any attempted assignation of 1M with 1L or 4M with 4L for 24 bars. 1s and 4s cannot meet their partners since they are constrained to stay exactly the same distance apart during the parallel reels and the chaperons pass between them; the chaperons are ever present even during the hands across.
On bar 25, while the chaperons congratulate themselves on their success and take their eyes off their charges, 4th couple slip away and, on bar 27, 1st couple also take advantage of the opportunity to elude the chaperons.
On bar 31, the errant 1s and 4s return to the party as though nothing had happened. 

A chaperone (or occasionally chaperon) is an adult who accompanies or supervises one or more young, unmarried men or women during social occasions, usually with the specific intent of preventing inappropriate social interactions or other bad behavior. The chaperone is typically accountable to a third party, usually the parents of one of the accompanied young people. 

(Source: <<http://www.scottish-country-dancing-dictionary.com/dance-crib/chaperons.html|Scottish Country Dancing Dictionary>>)