Tonight, Obi-Wan Kenobi doesn't walk away from the river of fire on Mustafar. His friend lies burning on the black sand, and this time Obi-Wan turns back, raises his blade, and ends it. In the films, that man survives twenty-three more years inside a black suit. Some of the fire behind them was real, filmed on Mount Etna in two thousand two. And a real moon, Jupiter's Io, carries more than four hundred active volcanoes.