If you’re a manager in a knowledge-driven industry, chances are you’re an expert in the area you manage. Try to imagine a leader without this expertise doing your job. You’ll probably conclude it couldn’t be done. But as your career advances, at some point you will be promoted into a job which includes responsibility for areas outside your specialty. Your subordinates will ask questions that you cannot answer and may not even understand. How can you lead them when they know a lot more about their work than you do? Welcome to reality: You are now the leader without expertise—and this is where you, possibly for the first time in your career, find yourself failing. You feel frustrated, tired and disoriented, even angry. This is the point where careers can derail. If you get to this point, or see yourself headed in this direction, what can you do?