Gamayun tales / Utkin, Alexander

After a deal with Vodyanoy, the water spirit forces the merchant's son into a life of servitude under water. When a not-so chance encounter with Vodyanoy's daughter Tyna occurs, it may mean that the merchant's son now has a chance at freedom. They must survive long enough to plan an escape and avoid the creatures that lie in the deep blue.

"We rejoin our friend the merchant as he returns home from his adventure with the King of Birds. When curiosity gets the best of him and he opens his new mysterious golden chest, the merchant unwittingly condemns his newborn son to a life under the sea"--From publisher.