Headbang in the fight arena pub

Warning! Potential danger for hardcore ironman!

1. Go to the ::shops at home, trade the outfits store and buy a pirate bandana. You will need to craft a dragonstone necklace and a magic longbow. You need 72 crafting to make a dragonstone necklace and 85 fletching to fletch a magic longbow. 
2. City teleports > Yanille
3. Leave the city through the north and walk north-west, past the back of the fight arena until you reach a pub.
4. Equip above items and perform the 'Headbang' emote, a level 141 double agent spawns, kill it to finish the clue!