Osborne, Mary Pope. <br/><br/>
Dolphins at daybreak / 
by Mary Pope Osborne; illustrated by Sal Murdocca. 
 - New York, NY :  Scholastic, Inc,  1997. 
 - p.  cm. 
 - Magic Tree House; #9 .
<br/><br/> Summary: The magic tree house takes Jack and Annie deep into the sea, where they meet up with dolphins, sharks, and octopi as they search for the answer to an ancient riddle. 
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<br/><br/><label>ISBN: </label>0-679-88338-X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Time travel--Fiction<br/>Marine animals--Fiction<br/>Tree houses--Fiction<br/>Magic--Fiction