On the map
Silithus- not on the map
Progress
You've shown you're more than capable of taking on an Abyssal Duke, <name>. I'm always one to promote good habits. Bring me more signets and I'll give you a reward.
Completion
Excellent, <name>! Defeating those Dukes will leave the Twilight's Hammer reeling for a while. As promised, here's your reward. It's some of the better stuff Huum and I have found.