Before setting out to obtain any more magical items, it is best to gather some knowledge of the Harpies, as you will be facing down a lot of them in the future. For this purpose, you can head to the notice board in Vergen. The board is located right outside of the tavern. Pick up the Harpy Contract to initiate this optional, but recommended, quest.
Head towards the northern side of town after picking up the contract. When you reach the entrance to Vergen, take a left and head up the stairs. Follow the path around and you should find a series of markets and dwellings. Look for an NPC named Felicia Cori, and speak to her to obtain a book on Harpies. From here, loop back around the way you came and walk towards the southern end of town. Keep going past the valley containing the tavern, and past the entrance to the system of caves where you attended the war council. The walls of the city will come together to form a boot, which will be lined with dwellings. Proceed to the one home on the right side of the area and seek out an NPC named Earso. Inquire with him about purchasing some Harpy Traps. You will want to buy a fairly large number of traps, at least eight or nine, as they will help you not only with this contract, but with obtaining a crystal for Philippa as well.
Leave Vergen and enter the Pontar Valley region. Four Harpy nests lie in this area. It shouldn’t matter where you lay the traps as long as they are close enough to the Harpy’s nest, as the bait in the trap will attract a Harpy, who will then carry it off to its nest. After destroying the four nests in the spiraling crater, head upwards and towards the center. You will find the entrance to the Harpy’s Lair. Three more nests sit inside this area, on top of the ravines. Complete the same process of setting a trap near each nest and waiting for a Harpy to take the bait. The first nest should be located just around the first turn in the cavern. The next will be right after the 180 degree turn in the path. The third and final nest rests near the end of the widest area of the path, right before the exit.
Destroying all of the Harpy’s nests will earn you an ability called Birdman, which will increase your damage output against Harpies by 10%. Return to Cecil to receive 100 experience points, along with 200 orens and a fire rune.