Legendary magician David Copperfield took the stand in a Las Vegas courtroom last week. He's being sued by a fan who says he suffered traumatic brain injuries during a performance at the MGM Grand. Gavin Cox is suing Copperfield, the MGM Grand and a construction company, all of whom deny that they're to blame. Copperfield took the stand and was forced to pull back the curtain on his famous illusion and revealed how he did it.