While Agent Skully appears human she is in actuality a Forsaken disguised to appear as a member of the Scarlet Onslaught due to the use of a Magic Mirror. Her mission is to discover the Scarlet Onslaught's strange immunity to the New Plague as well as any other plans they may have which could hinder the Hand of Vengeance in their goals. Her exact position is as the Onslaught's Cemetery Caretaker which allows her to hang out behind the chapel and closely examine any of the recently deceased.
For Horde players she has four quests which give you the opportunity to assist her in uncovering just what is going on with the Scarlet Onslaught and the strange new "blessing" they are being provided by their "Bishop". The first quest Without a Prayer sends you after the Bishop's prayer book. (What is interesting about this is for Rogues for the first time in a VERY long time you can actually Pick Pocket the item off the Bishop.) The Perfect Dissemblance allows you to also play with the mirror for a short time. (Druids have a hard time with this quest as they often forget to shift out of form first causing the mirror to fail.) A Fall from Grace tends to take players by surprise (I won't spoil the punch line for you) but I do like Skully's line when you report to her following it. The Truth Will Out is Skully's final quest for players. (Another X-files reference) Take the time to read the General's Diary if you would like a more complete understanding of what is going on.
Some of you might be wondering if Skully is at New Hearthglen, where is Molder? Well don't fret, her old partner is not far off. Deathguard Molder can be found at Venmonspite. What is truly scary is that they actually changed his model so he looks MORE like David Duchovny.