You can explain most comic-book superheroes in one sentence. Alien from Krypton is indestructible under Earth's sun. Billionaire builds super gadgets, costumes and vehicles to beat up criminals. Teenager gets bitten by spider, can climb walls and shoot webs. And so on. Green Lantern is a little more complicated than that. It involves aliens, outer space and mental constructs. Maybe that's why screenwriter Greg Berlanti is describing it more like Star Wars than Superman.