Heart of Deimos will also introduce you to the Entrati Family as you perform various tasks for them, such as destroying Infested hives and collecting glowing residue from the Cambion Drift itself.

You will also be tasked with a bit of spearfishing. You can use your own fishing spear purchased in Cetus, but you will be provided with a temporary spear to use in the meantime if you do not. Either way, you can equip it via your Gear Wheel (just like a Codex Scanner). Aim and throw the spear to catch any flying fish that breach the exocrine: the solid, translucent “river” that runs along the surface of Deimos.

Once you finish your fishing and return to the Entrati, you’ll be directed underground to a secret section of Deimos protected by a locked vault door. The door sports a combination lock of sorts.

To open it, you need to watch the symbols that appear on the door and activate the matching pedestals in the proper order. Follow the sequence of the symbols that appear on the door in order from top to bottom to unlock the vault! Don’t worry if you fail. You can retry as many times as necessary.

On the other side of the door is a deadly rogue Necramech. You’ll be too weak to fight it at this stage, so follow the Entrati’s instructions and return to the surface. You will temporarily receive your own loaner Necramech to fight back against the frazzled machine.

Fight your way back to the rogue Necramech — destroying any marked Infested that bar your way. When the way is clear, you’ll receive a repair tool called an Omni. Fire it at the titular Heart of Deimos to repair the device.

This will attract the rogue Necramech once again, but your own war machine will allow you to fight back. Aim for its shoulder joints, face plate and the glowing blue crack on its back. You’ll eventually wear the opponent down and finish Heart of Deimos! With the quest complete, you will earn a Xaku Blueprint and full access to Bounties and other activities in the Cambion Drift and the Necralisk hub.