Osborne, Mary Pope. <br/><br/>
The knight at dawn / 
by Mary Pope Osborne; illustrated by Sal Murdocca. 
 - New York, NY :  Random House,  1993. 
 - p.  cm. 
 - Magic Tree House; #2 .
<br/><br/> Summary: Eight-year-old Jack and his seven-year-old sister, Annie use the magic tree house to travel back to the Middle Ages, where they explore a castle and are helped by a mysterious knight. 
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<br/><br/><label>ISBN: </label>0-7857-0303-9 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Time travel--Fiction<br/>Adventure and adventures--Fiction<br/>Tree houses--Fiction<br/>Knights and knighthood--Fiction