Morgan le Fay will make Jack and Annie masters of the tree house if only they can solve four riddles -- which will take four books, of course! <i>Dolphins at Daybreak</i> begins the third set of four books in this magical (and increasingly popular) series!  Jack and Annie are off in the Magic Tree House again, this time to a whole new world under the ocean.  Complete with a giant octopus, a hungry shark, and dolphins to the rescue, this Magic Tree House book delivers an underwater adventure kids can dream about.