

In the original version, Nancy has changed clothes, so only George knows what Nancy and Bess were wearing when they disappeared. Her discovery of a dress button Nancy has planted at the scene is downplayed. Drew is nearly as instrumental in finding Nancy as George. Strangely, the revision also eliminates the importance of George's recovery although she leads investigators to the scene of the kidnapping, Mr. Additionally, the revised version removes questionable (in 1969) descriptive elements of George's drugged status and hypodermics.

Nancy's haircolor is changed to titian, George's from black to brown, and eliminates subplots and extraneous descriptive vocabulary, including non-essential scenes and passages, including humorous passages where Nancy works undercover as a file clerk and finds the work unappealing. (this refers to an out-of-print version of the story). George Fayne is drugged and a victim of criminal threat, and Ned is involved in two physical confrontations as well. This volume seems to be one filled with physical action, finding Nancy repeatedly assaulted or engaged in physical confrontations. She must overcome her mental breakdown and get on the case when the girls fail to return.

Only paranoid George knows where they are, and can identify the clothing last worn by Nancy. She and Bess investigate the ramshackle Blue Iris Inn in the nearby countryside, and fall victim to the evil Velvet gang. She realizes that the numbers actually mark dates of events at which robberies took place.

Tombar, while she attempts to decode mysterious numbers written on the lining of the mask. Nancy focuses on the executive assistant at Lightner's, Mr. Nancy and George rent wigs to switch identities however, George is kidnapped, her disguise removed, put under the influence of hypnotic, mind-altering drugs, and threatened. At subsequent Lightner events, Nancy encounters other thieves, and is nearly suffocated by an evil pair of crooks. Her acquaintance, Linda, who is an employee of the Lightner company, is suspected of wrongdoing. At the party, Nancy finds an odd, black, velvet hood, which she retains as a clue. As the story opens, Nancy and friends attempt to thwart suspicious, masked party-goers from reaching valuable objects d'art on display.
