The utopian world carefully created by Denver cab driver Brendan Murphy is about to be shattered. In fact, it's about to be the worst day of his cab driving career. There's the Land That Forward Motion Forgot. There's a guy Murph comes to think of as "Mister Twenty." And there's an old woman who wants to pay her fare with a saucepan full of pennies.In "Dark Night of the Soul," the sixth adventure in The Asphalt Warrior series, Murph's plan to carefully monitor the intake of cash—for fear of earning too much—challenges every math skill he can muster. Messes grow around Murph "the way a pearl grows around a pebble." Of course "it's best not to think about what might have happened if you had done this instead of that," but it's hard not to wonder went wrong when you're kissing the asphalt and police have surrounded you with guns drawn.To wriggle out of his latest spot, Murph must stare long and hard at who he is and what he's all about. It's the most eye-popping journey of all time.