The Underfoot Depths raid is designed with four groups of level 90 characters in mind, and features a large zone and wide variety of mob difficulties. The zone is so large, and the mobs so brutal, that designers extended the lockout time to four days and twenty hours (up from the standard two days/twenty hours) to allow players the option of running the zone's gauntlets over multiple days.
"The named encounters will be challenging and require some tactics be applied. If you manage to reach Master Yael himself, you'll be ready to take on the most challenging encounter yet," proclaims the press release. You can view the article, along with a selection of images from the new raid, over at Sony Online Entertainment's official Everquest II website.