Warner, Gertrude Chandler,  1890-1979. <br/><br/>
The disappearing staircase mystery. 

 -  Scholastic Inc.,  2001. 
 - Boxcar children ;  [#85] .
<br/><br/>
<br/><br/><label>ISBN: </label>080755491X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mystery and detective stories.<br/>Brothers and sisters--Fiction