Long before we learned about their past in three underwhelming prequels, Obi-Wan Kenobi and Darth Vader met in perhaps the most epic light-saber duel in the series. Midway through Episode IV: A New Hope, Obi-Wan, whom we met as a hermit named Ben Kenobi, confronts Darth Vader, the evil forces commander of the Galactic Empire. Writer and director George Lucas gives us just enough information. “When I left you, I was but a learner,” Vader says. “Now, I am the master.” The fight between two battle-scarred warriors way past their prime is slower and clumsier than the climax of Episode III: Revenge of the Sith, yet the first on-screen clash between the master and his former pupil is the most intense. After grappling, not just for position and advantage, but for each other’s souls, Obi-Wan tells Vader, “If you strike me down, I shall become more powerful than you can possibly imagine.” When Obi-Wan yields and Vader moves in for the kill, Obi-Wan disappears, setting up the great mystery that drove the series for two more classic films.