After Rolfe prepares the gift of milkroot for the sylphs, he advises you to consult with Amelain before your first foray into the sylphs' territory.
This quest is available if you have completed the quest First Impressions, and have reached level 21.
Starting the Quest
Talk to Rolfe in the Hawthorne Hut in the East Shroud to start the quest. There will be a cutscene.
Speak with Amelain
Talk to Amelain to receive a letter from the Elder Seedseer for you to deliver to the sylphs.
Speak with Komuxio
Go out by the south exit of the Hawthorne Hut and go east to reach Little Solace. Talk to Komuxio.
Perform a /dance for Komuxio
Target Komuxio and type
/dance motion (the second one will not display a chat message)
to dance for Komuxio.
Deliver the Milkroot and Letter
Talk to Komuxio again to hand over the milkroot and letter. There will be a cutscene.
Next Main Scenario Quest
After you complete the quest, talk to Yda to accept the next quest: Dance Dance Diplomacy.