Destiny 2's Ralnik's Hatchet is an item you need to locate as part of a quest.
As you explore the Moon, you'll pick up a variety of 'Essence' quests, with a variety of Moon and Nightmare-related tasks.
One of these is Essence of Jealousy, which you can pick up from the Lectern of Enchantment, with one of the steps is finding the Ralnik's Hatchet within the Traitor's Ketch.
It's a location not on the map, so you might need some pointers of where to find it.
Where to find Traitor's Ketch in Destiny 2
First, let's get to the Traitor's Ketch, which is a location that's technically visible on the map, but is not actually named.
To get there, head south-east from Anchor of Light. On the map this is a giant ship - and it's just as hard to miss when actually playing.
Head inside and once you've made it several rooms in, you'll be at the Traitor's Ketch.
Season of the Lost is here, with new Exotics such as the Ager's Scepter and the long-awaited arrival of crossplay. New activities include the Wayfinders Voyage, the Astral Alignment activity and finding Atlas Skew, Trivial Mystery, Enigmatic Mystery, Ascendant Mystery, Data Cache, Parallax Trajectory and Ascendant Anchor locations. Elsewhere, we've seen new Nightfall weapons such as the Uzume RR4, Plug One.1 and Hung Jury SR4. Other recent new features include transmog and materials Synthstrand, Synthcord and Synthweave, the Splicer Gauntlet and Decrypted Data used to upgrade it.
Where to find Ralnik's Hatchet in Destiny 2
Once inside Traitor's Ketch, finding Ralnik's Hatch works a little differently compared to other Essence items.
In this room you'll have to kill a specific enemy for it to drop, named 'Ralnik's Blood of Kells'.
It's a large yellow bar enemy that spawns at the far end, just before the door to the next area. Take it down and Ralnik's Hatchet will be collected straight away.