Purpose. It's the word that's becoming important to the characters of "The Leftovers." In last week's "Solace For Tired Feet," Kevin Garvey's (Justin Theroux) father tried desperately to lift the veil from his son's eyes, to get him to see the true reality of what's going on around them. But due to his old man's unhinged manner, Kevin either refused or simply couldn't see what his father tried to put in front of him. And in this week's "Cairo," he's once again brought to the edge of understanding, with that word "purpose" reappearing, almost like a weapon, before the situation spins out of control, with even more left for Kevin to puzzle over.