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