Keene, Carolyn. <br/><br/>
The clue of the velvet mask. 

 - New York  Grosset & Dunlap  [1953] 
 - 211 p. 
 - Her Nancy Drew mystery stories, 30 .
<br/><br/> When a gang that uses parties as a cover for robberies victimizes a masquerade party Nancy is attending, the teen-age detective switches identity with her girl friend to solve the case. 
<br/><br/><label>LCCN: </label>69014266 /AC/r84 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mystery and detective stories.
<br/><br/><label>LC Class. No.: </label>PZ7.K23  / Nan, no. 30 1953 
<br/><br/><label>Dewey Class. No.: </label>[Fic]