Atlantis, once the most amazing city in the entire world, has been hidden deep inside a volcano under the ocean for more than 5,000 years to protect it from those who want the amazing secrets of the people inside. The gates to the city have been locked so no one can enter. Now, it is time for Atlantis to rise from the bottom of the ocean and take its place among the other great cities of the world. But the people of Atlantis can't make this happen alone. Three children - Kevin, Sarah, and Grayson - are asked to help a mysterious Traveler and his two magical guides journey to the far corners of the galaxy to find the first of twelve keys needed to open the secret gates that hide Atlantis. But the children are being watched. Someone wants the keys to Atlantis for themselves. Can the children find the keys in time to help Atlantis and her people rise from the bottom of the ocean?