This quest will unlock after you complete the Hunting for the Lodge Errand. Talk to Talanah then follow her outside and talk to her again to start the quest properly. Apparently Lone Light is under attack from Machines and have requested the help of the Hunter’s Lodge. So head up to Lone Light and when you get there you’ll find the place under attack by Glinthawks.
The usual Glinthawk strategy of shooting their Freeze Sacs with Tearblast arrows then critical hitting them when they fall from the sky should suffice, although if you have a Ropecaster two ropes will bring the Machines to the ground for easy damage as well. However you decide to deal with them, they’ll come in waves of three or four and once they’re all dead, talk to Talanah and Ilsadi. From that conversation you’ll get the objective to head for the area full of dead Snapmaws. Follow your marker to the location, where two more Glinthawks will be feeding. Take them out, then climb up the cliffs beside the Snapmaw mass grave.
At the top you’ll find some Carja Hunters who are looking for Snapmaw hearts. They’re a bit prickly, and you can either decide to kill them, or you can help them get the last Snapmaw heart. If you decide to do the latter, follow your objective marker down to the river where there will be two Snapmaws. Kill one or both of them to get the heart then head back to the Hunters.
Hand over the heart and they’ll decide to leave peacefully. Once the conversation with Talanah ends, head back to the Hunter’s Lodge and talk to Ahsis to finish the quest.