Blood Ties: Oliver Nocturne, Book 3

Blood is thicker—and more tempting—than water
Finally, school's out for summer. To avoid the lethal sun, the Nocturne family is taking a trip to Isla Necrata, the exclusive resort owned by the Half-Light Consortium, whose destinations are always located near a natural disaster, which makes for plenty of vampire fun.
 
But for Oliver, it's hard to look forward to a big dose of time with his family when everything he does seems to disappoint them. Luckily, they stop to visit some Old World relatives in Morosia on the way. Though Oliver's grandparents may be bloodthirsty and gothic, at least they still seem to like him. And the timing is convenient: Emalie is in nearby Rome searching for the oracle who may be the key to Oliver's prophecy. But what the three friends discover in the ruins of Rome and the dark passages of Morosia will forever change their understanding of Oliver's destiny and the dangerous lengths to which Half-Light would go to see the prophecy fulfilled.