Swindells Robert E  1939 <br/><br/>
When darkness comes. 

 - New York,  Morrow,  1975  
 - 158 p.  illus.  22 cm. 
<br/><br/>  A primitive band of people splits into two warring factions until the arrival of a common enemy unites them. 
<br/><br/><label>ISBN: </label>0688220169  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science fiction
<br/><br/><label>LC Class. No.: </label>PZ7.S9818