In this fifth and final book of the Percy Jackson & The Olympians series, the war pitting the Olympian gods against Kronos and his allies is in full swing. The legendary (and legendarily powerful) monster Typhon has escaped and is wrecking havoc all across America; Percy finally reads the full Great Prophecy that's been hanging over his head since the first book; and eventually everyone - allies and enemies and everyone in between - converges to Manhattan for the Epic Final Battle.
Of course, since this is a final installment and there's an Epic Final Battle, deaths are a-plenty (which is only to be expected, really).
It was very good; as with the previous installments of this series, I found it hard to put down the book once I'd started it. So yes, I do recommend it; in fact, I'd even recommend reading the entire series. Come on, there's Greek mythology involved!