Shadow of Fear is the upcoming content installment for EverQuest! It will consist of 2 zones (Plane of Shadow, and Chelsith Reborn). The content will be free to those who have purchased the Rain of Fear expansion.

There will be new Alternate Advancement Abilities for all classes, as well as new spells and disciplines. You can view a full list of your class' new AA's and Spells by clicking on the link for your class on the Menu to the left!

Here is a quote from Phathom on the topic:

Quote: Phathom, Producer's Letter
"Last year, we launched the Rain of Fear expansion (EverQuest's 19th Expansion) and in April, we will be continuing the Rain of Fear story with the Shadows of Fear Game Update. Shadows of Fear will be available to everyone that has purchased the Rain of Fear expansion. It will include some new zones while introducing some new storylines of godly proportion and you will have some Spell and AA lines that you haven't had before."