"Helen of Troy" (9 p.m., PBS): Historian Bettany Hughes travels across the eastern Mediterranean on

"Helen of Troy" (9 p.m., PBS): Historian Bettany Hughes travels across the eastern Mediterranean on an epic journey to discover the truth about the ravishing beauty who has been blamed for causing the Trojan War. From the mountains of Sparta in Greece to Turkey, where the city of Troy is said to have stood, Hughes looks for clues about a woman whose face "launched a thousand ships."
"One Tree Hill" (8 p.m., WB): The gang celebrates the beginning of its senior year with a beach party. It'd be a cool bash if these people weren't pushing 30.
"Lost" (9 p.m., ABC): The raft castaways find out who is holding them hostage.
"Stoked: The Rise and Fall of Gator" (9 p.m., Starz): Before there was Tony Hawk, there was Mark "Gator" Rogowski. But the man who dominated the '80s skateboarding scene took a tragic turn somewhere in life. Gator is now serving 31 years to life for the rape and murder of a young woman. This documentary retraces his missteps.