The Secrets of a Top Business Turn-Around Agent

What is it that makes it possible for a Top Business Turn-Around Agent to go into a business that he or she knows little to nothing about, and that operates in an industry of which the agent has no prior experience and yet, is able to turn the struggling business around from perhaps even near bankruptcy levels onto a path of prosperity in matters of weeks or a few months?

How are they able to do this, when the business owners may have been at it for years and still haven't been able to make the business profitable again?