You’ll pick this one up from Balahn, the Captain of Daytower. Follow your waypoint to the Corrupted Zone. If you’ve already cleared it, it will still be clear, if not, clear it out now to save yourself the hassle of sneaking past the machines. Investigate around the marker until you find a Carja soldier’s body, examine that then follow the tracks. Eventually you’ll reach a series of bloodstains on the shore of a lake. Swim to the nearby island to pick up the trail again, and follow it to a cliffside where you’ll find the missing Carja soldier, Lakhir. He’ll tell you that he lost his bow, and he wants it back before he’ll head back to Daytower. This means you’re going to have to fight a Snapmaw. Luckily, the ones here have exposed Blaze canisters behind their heads, so get your fire arrows and shoot the canisters for an easy kill, then loot the body.
Be aware that there are Scrappers in the area, and your fight with the Snapmaw may well attract their attention, so be ready to fight them off if need be. Get the bow, and give it back to Lakhir to complete the Errand.