ok. here are some of the ideas i got off of the internet about the whole leo/ sammy valdez thing.
1.leo is sammys grandson on his moms side.
2.leo is sammy reborn from elysium.
3.sammy got stuck in the lotus casino and some how his name changed to leo.
4.leo slept for half a decde like percy did for eight months.
5. as sammy, leo changed his name as he moved around to keep hidden.
6. gaea created an illusion on hazel to make her think leo is sammy.
7.leo is sammys long lost brother.
8. sammy is hephestus in disguise.
9.sammy is a son of hephaestus that was never claimed and leo and him both have mothers from the same family
10.hephaestus loved leos mother so much that he granted her a longer life... in the forties and she is leo AND sammys mom.
i hope these were helpful! angel signing off. percy geeks unite! annabeth cant die! i think nico does die. THE END BEFORE I START RAMBLING ABOUT EACH AND EVERY ONE OF MY OPINIONS ON THE MARK OF ATHENA@!!!! K BYE