Turbine says the event is unlike anything you've seen before in Dungeons & Dragons Online.

Turbine is planning to give Dungeons & Dragons Online players a sneak peek at a new Halloween-themed live event for characters of all levels on the Lamannia Preview Server tonight, Sept. 30, at 7:30 p.m. EDT. According to the announcement, the two-phase event is unlike anything you've seen before in DDO. The first phase takes place in Delera's graveyard, while the second phase involves a unique boss and instanced gameplay.

If you choose to participate, try to take a screenshot of your character dancing with a DDO developer for a chance to win prizes like signed concept art, a Turbine Fleece Vest, Turbine Points, or Eberron Unlimited launch day mugs!

All the information you need to access the Lamannia server can be found in this thread on the official forums. Remember that the event is being held for testing purposes, so there's a chance things may not go as planned. If you can't make it, you can just wait until the event goes live.