Gotta flame on the contractor species. Embedded journalists (like those you saw during the most recent invasion of Iraq), were there to protect themselves and share the information that they learned with the world. On the other hand, and Embedded Contractor is someone that works a contract for a long time and learns information, but DOES NOT share that information in an effort to protect themselves.
Often this person has a reputation as being able to fix the problems that no one else can. They are also allergic to documenting anything that they do, commonly stating that they need to fix some critical issue, and won't have time for things like documentation. This type of person will make new team members look bad in an effort to make themselves look good.
This gets even more fun when they know that the newly hired person was hired specifically to replace them. I hate being the new person. It's like pulling teeth on a bull.