You may find an abandoned groove while exploring the Howling Plateau and you'll notice an injured guard lying on the ground next to the entrance. Enter the underground location.
Kill the Lacuni attacking the Iron Wolves
Kill all Lacuni Huntresses found in the dungeon. They should be fighting the soldiers.
Return to the Iron Wolves Commander
Once you've killed all huntresses locate the commander using your map and report your success.
Kill Ghas and the Lacuni
New monsters will appear after a short conversation. Attack a group Lacuni Huntresses and a large Ghas. Just as before, you can count on the soldiers to help you. Defeating this group of enemies will end the event.