This is a support quest for Throw the Dice quest. You will get it automatically when you approach the Cave of Pan while doing the Throw the Dice quest.
One of the recovered maps leads here, to the location of the legendary flute of Pan.
Pan's Flute
Objectives of Pan's Flute
1. Explore the Cave of Pan in Attika
2. Acquire Pan's Flute
3. Quest Completed
Rewards: Epic XP, Legendary Drachmae