The Case of the Lost Mermaid - The Wolflock Cases, #6

The Case of the Lost Mermaid is the sixth book in the Wolflock Cases teen fantasy mystery series. Wolflock owes his life to a mermaid he may have accidentally doomed. The only way to save her is to find the mythical mermaid city of Sinalta without delaying the ship. But the cards of Faleen and Bleen have foretold disaster in his fate. Is their interference to save his life or do they have sinister intentions? To make matters worse, he has to make a choice: repay his debt by delaying the ship or leave the mermaid to perish in the icy sea.
Unfortunately, if he can't solve the case in two days, he may no longer be able to choose.