Instructions
Proceed through the game until you've reached level 20. If you're under level 20, you can speak with Ben the farmer, but he won't offer you the Red Dahlia quest.
Travel to Henesys, which is located on the far south side of Victoria Island. There you'll find Thomas Swift in the Amoria Embassy. Speak with him to go to Amoria.
Click on Ben the farmer. He's holding a pitchfork in one hand. His other hand is in a cast. You'll find him in the gardens in the middle of Amoria. He'll give you the Red Dahlia quest.
Gather three diamond ores and 30 stiff feathers. You can find diamond ore at the Amoria shop, Cupid's Corner. Each one costs 300 mesos. The stiff feathers are dropped by dozens of enemies, including Wild Boars, Desert Rabbits and Dark Yetis.
Return to Ben with the items. He'll reward you with 668 experience points and a glove augmentation scroll.