The Siren Song is by Anne Ursu. The second book in The Cronus Chronicles series. Charlotte and her parents win a cruise up the Atlantic coast. There's just one problem, the contest was rigged by Poseidon who is upset with Charlotte for defeating his grandson Philonecron. While Poseidon goes after Charlotte, Philonecron kidnaps Zee and takes him to Poseidon's yacht. Now Charlotte must rescue Zee and save her family by defeating the second most powerful god in the pantheon.
Ratings: 7th grade - 9 out of 10.