Dragon's Bluff — Mary H. Herbert

The port town of Flotsam has always been left to handle its own problems, neither asking for nor wanting help from the rest of Krynn. That is, until the young mage Ulin Majere and his traveling companion are summoned there to identify a murder victim. They quickly discover there is more to the rough seaport than just one dead body, including cagey thieves, failing magic, the Knights of Neraka, and a very greedy, very deadly red dragon.