**SPOILERS** ( You have been warned...)
<u><em>Prophecy: Seven half bloods shall answer the call,</em></u>
<u><em> To storm or fire, the world will fall, </em></u>
<u><em> An oath to keep with the final breath,</em></u>
<u><em> And foes bear arms to the doors of death.</em></u>
The Seven Demigods of The Second Great Prophecy are:
Perseus (Percy) Jackson, Annabeth Chase, Leonidas (Leo) Valdez, Piper McLean, Jason Grace, Hazel Levesque, and Frank Zhang.
They go on a quest to close the doors of death, bring peace between the Greek and Romans, but overall the reason for their quest is to defeat the Goddess Gaia.
Out of the seven, Leo Valdez die in the explosion that destroyed Gaia, but due to the Physician's Cure, Leo came back to life, and freed Calypso from her Island. This fulfilled the part of the prophecy " ....an oath to keep with the final breath."
This is not a myth, but based upon tales from Greek mythology. It includes characters, such as Hercules, Gaia, and The Olympians, from the myths.
No, this is not a true story. (From what mortals believe...;) )