The Naethari Chronicles

Jonathon Chan was stuck in a hospital, dying from leukemia, when he was approached to test a secretive new Cancer treatment. He never expected it to work; he just wanted to put an end to his suffering. He certainly didn't expect to wake up as a girl, let alone a mythical creature. Now he's been turned into some kind of mermaid and is being held captive in an underground pool with three others in the same boat. One of those prisoners is able to explain that they are not mermaids, but Naethari, an ancient race of magical beings from another world.

Can Jon, now Naiya, and her fellow captives escape their captivity and earn their freedom? They have a plan, but it's going to take work, learning to use strange new abilities, and some help from family and a new friend. Anything to avoid spending the rest of their lives in a marine park doing tricks for paying audiences, even if they have to pretend to be dumb animals to make their captors underestimate them. They just need to keep up the act and wait for an opening. But even if they do succeed and regain their freedom, can they keep it?