Quite possibly the most disjointed, ridiculously far-fetched and "one-sidedly dramatic" Nancy Drew I've read yet.
Right at the beginning, Nancy's about to go to a masquerade party, and Carson Drew just happens to mention that there's a gang that shows up at masquerade parties and steal valuables while they're in disguise. My, my...there's a one in a hundred chance of that happening to Nancy, right now, right? Just because she's Nancy doesn't mean...
But it does! At the party, the lights suddenly out and stuff is stolen! Nancy and Ned know a costumed figure climbed up a trellis to a second-story window, but they weren't able to get help. Nancy's only clue is a black velvet hood-mask, with eye holes.
The costumes at the party were all provided by Lightner Entertainment Corp., a party rental/hosting company. The company has been troubled lately, and some people are wondering if someone in the company is involved in shady deals. Meanwhile, an employee of the company, Linda Seeley, is one of the high suspects, but Nancy knows she's guiltless. Of course she does. As Nancy gets more deeply involved, she goes to more parties organized and supplied by Lightner....and more things happen. Mysterious men are following Nancy. Some of them try to get into the house, as always.
Everyone's convinced that Nancy's going to be mugged, so George has a *great* idea--she'll dress as Nancy, and Nancy as her! I guess the idea was, Nancy will be able to sleuth freely, but I just thought, instead of one girl getting mugged, another one will. Great chivalry, George, but kind of stupid. Nancy has to stop sometime.
And of course, George is mugged, drugged, and when the ruse is found out, she is threatened that bad things will happen if Nancy continues to sleuth! Thus, when George is found, instead of saying something right away to alert the police, George has a breakdown and is ordered to take it easy. She tells Nancy to stop sleuthing, but doesn't give a reason.
Baffled, Nancy keeps sleuthing...is kidnapped...and George, scared for her friend, gathers her strength and tells them what happened, so they can all use her clues to figure out where Nancy is! And, of course it all comes out right in the end.
