Skill: Dust Trap

I still consider myself new to factions and I'm trying to form a trapper. I have all of the traps except for Dust Trap. I have no idea which boss has it and the skill npc doesn't sell that skill. I tried doing some research but most of the sites refer to the town dorks and I don't have that town in my faction. So I'm asking anyone out there if they know which boss have this skill to let me know, thx for the help.

http://gw.gamewikis.org/wiki/Dust_Trap
Check out the bottom for skill locations and quests.

sorry bee, Dust trap is a "Profecies Only" skill.

i see, thx for the help.