This used to be my favorite Nancy Drew mystery. It's a fun mystery, but the plot and events are hilariously corny. I think I can summarize it quickly...
Carson Drew's case, involving "Monsieur LeBlanc"'s mysterious financial habits, is almost completely given to Nancy. Nancy is also doing an exchange program with Monique and Marie, two girls from France. Their aunt just happens also to live in River Heights, and she has a mystery for Nancy, too.
Aunt Josette has a weird recurring dream of falling down 99 steps in Paris, where she lived when she was a kid. Aunt Jossette hopes Nan will help her get closure by finding the stairs, and stop the dream.
Nancy and Bess and George go to France--after several attempted break-ins, threats from a mysterious "Monsieur Neuf" (Neuf=#9), who also puts a sign in Nancy's car--"Beware the Green Lion!". According to the story, in the Middle Ages "green lion" was a code for an acid that destroys gold. Also in the Middle Ages, people were trying to turn lead into gold. :P
After randomly looking around for 99 steps, Nancy finds it at a random ruined chateau. It turns out that Aunt Josette's childhood au pair was married to Louis Aubert, who tricked Monsieur LeBlanc into thinking coal could be turned into gold. Louis managed to LeBlanc to sell all of his (LeBlanc's) fortunes in order to purchase diamonds--so that when everything "became gold", the price of gold would collapse and they could sell diamonds for millions at a profit. Not only is LeBlanc very, very stupid, so is Aubert. Even though he might trick LeBlanc into giving him tons of money for the "experiment", LeBlanc is pushing Aubert to introduce his "experiment" to the public. LeBlanc's trick is covering gold with charcoal and then firing it off. You'd think it would be a short-lived trick, right? Wouldn't LeBlanc see past it? Nope. This is a very very clumsy mystery.
Moving on! It is revealed that when Josette was little, her au pair (who is found alive and well in France) was in love with Aubert and dated him.. One day, she had to take young Josette to the lab so she could be with Louis, but didn't want Josette to know about the lab. The au pair blindfolded Josette and pretended they were playing blindman's bluff. She started to lead Josette to the steps, but Josette stumbled and fell down the stairs. Josette was unhurt, but was (understandably) really traumatized.
The bad guys are arrested--the au pair is sorry and is innocent--and all is well.
- Nancy attracts the attentions of Henri, an attractive young man, at a ball. Henri later helps her try to catch a disguised Louis Aubert. Aww, too bad Ned doesn't know. :P
- During a tour of another historic site, an overweight woman almost causes an accident, making the girls stumble down the stairs. This woman is very rude and annoying. Because overweight people are always crude, selfish people, you know.
- Nancy saves a little boy who climbs on a statue of Joan of Arc to see a parade. Everyone cheers for her.
- As mentioned, there's no Ned. No Burt or Dave either.
- The girls talk about Joan of Arc. "Joan was seventeen when she requested [supplies] to help fight the English invaders," said Nancy. "I bet he laughed at her," George remarked. Then we get a history lesson--complete with dates. Really. These "history lessons" are worked into the girls' conversations, common in the Nancy Drew international mysteries.
Next: Taking a break from Nancy's exploits with a recap of one of my favorite childhood horse stories: Thoroughbred #1: A Horse Called Wonder