Hello GM,
'Wave One' quest is bug.
Location: Mount Hyjal, inside Firelands Hatchery
NPC: Farden Talonshrike

Bug: I cannot kill 10 Twilight Riders, and quest you cannot go out without completion of the quest. The only way to go out is using 'Character unstuck' or 'Heartstone' or Teleportation.

In addition, you cannot go for another quest lines.

Thanks.

Shadownourne