Emerald Knights
The Emerald Knights are a group of primarily Paladins and Rangers based at Corik's Wall who are fighting the Dark Hand. Their establishment is extensively documented in The Emerald Chronicles by Geoff Graev.
Membership is obtained by completing the Corik's Wall quest. The first two tasks involve restocking the herb and weapon supplies of the Corik's Wall guards. These items can be foraged or bought prior to obtaining the quest. Rangers, at least, have to provide 20(?) longbows, so it is often helpful to carve them prior to obtaining the quest. The third task, given by Captain of the Watch Grimnur, involves defending the Wall from an onslaught of Shadoweavers and Wormwood Vines. The messaging, when the quest is given, makes it sound as if all one has to do is to survive for one anals, but there is a minimum number of invaders that the defender must strike the killing blow upon. If memory serves, only Shadoweavers have this counter.
Upon completion of the quest, you will be given a badge which stays on your person through departs and provides you access past the Wall at any time.
Crest
A laurel and lion's claw on a verdant field. A brass badge etched with a laurel and lion's claw crest.