A deep rumble shakes Dereth as the Dark Isle begins its slow rise from the bottom of the sea.
In the depths below the Temple of N'cthail, the Soul Crystal of the Dark Isle shatters! The ancient Falatacot seals fall away as the flows of magic north of Vissidal slowly right themselves.
Long ago, Grael, the Black Spear of the Kemeroi, chose to sleep. The place he chose to sleep was an isle north of here, north of Vissidal Isle. His presence covered the island in Shadow, and the isle soon came to be called the Dark Isle. Those Falatacot who followed the Old One, N'cthail took a chance and used ancient seals to sink the isle below the waves. It was their hope that none would ever wake Grael and that this world would be free of him forever. Now, however, that wish has been undone by another. -- Kiriel Shadowborn
Access to Dark Isle is accomplished via the Dark Isle Flagging quest. It is recommended you lifestone on Dark Isle, there is no convenient portal back. Portals do exist though, on the far east end of Vissidal at 75.8N 70.2E or you can also repeat the flagging quest.
Unique to Dark Isle, all creatures spawn in pods of 4. One of the four will spawn a boss creature plus two more of its own kind on death. These boss creatures always drop a trophy worth at least 13 million xp (the ones from the inner island are worth 17). There are three NPCs that accept these trophies.