Excellent read with some references to strong drink.
Plot
The four Pevensie children are called back to Narnia to stand beside the Telmarine prince, Caspian, to rid Narnia of her oppressors and restore it to harmony.
Morality
Good is good and bad is bad throughout the story. The Telmarines oppress the Old Narnians and are, in general, cruel; the Old Narnian creatures like Trufflehunter are faithful to Aslan and believe in doing what it is right. Other creatures, impatient with waiting for freedom from their oppressors, are willing to turn to the forces of darkness and enlist their help, but their actions are punished and not condoned.
Spiritual Content
This story has, probably, the least spirituality of all the Chronicles of Narnia, though still with definite Christian parallels. The most obvious lesson in it is the importance of following Christ, even if you have to follow Him alone.
Violence
There is a battle against the Telmarine oppressors, but nothing graphic. It is also mentioned that someone wants to kill Prince Caspian. A murder is referenced, and a werewolf who shows up speaks of drinking blood and killing.
Drug and Alcohol Content
Bacchus, known to us as the Roman god of wine, visits Narnia at one point and consequently there is a great deal of drinking. Despite common opinion, however, there is no actual drunkenness at this point.
Sexual Content
None, though some people might take the women dancing during the festivities that way.
Crude or Profane Language or Content
"By Jove" is used by Peter. Trumpkin exclaims "Boots and bedbugs" and other such things.
Conclusion
'Prince Caspian' is a very clean story. The morals and spirituality are good, though the allegory is not as deep as in the other stories. The part with Bacchus and the references to drinking sometimes makes people nervous, however. Many people consider Bacchus and the rest to signify the joy that comes with the presence of the Bridegroom (portrayed by Aslan). As a lot of the story happens in flashbacks, it is not normally considered the best of The Chronicles, but is still an interesting read.