We've all seen them.
The sergeant, the administrative assistant, the executive secretary, the technician, the what-have-you who, while not being the highest-ranking person in a unit, has through expertise, information, and access, accumulated a great deal of power.
Those folks are the "go to" people. They regularly refute the notion that "If you want something done, go to the top." In their cases, going to the top would just complicate matters. It would add several layers and more confusion.
They sit like Buddhas, knowing the wise will come to their desk to find out what's really going on or to get help that goes beyond the verbal.
If you are going to be effective in any sizable organization, you need to learn the identities of those hidden powers and, if possible, cultivate a positive relationship with them. They can be powerful friends and formidable enemies.
In the organization's real organization chart, they are near or at the top.