Completing the Destiny 2: Lightfall campaign unlocks additional quests for new Exotic weapons, and one of those quests is called Unfinished Business, which rewards the Deterministic Chaos Void machine gun. A heavy projectile weakens targets on impact every fourth bullet and every 16th bullet makes enemies volatile when holding down the trigger. To start the Unfinished Business Exotic quest, speak with Nimbus after completing the Lightfall campaign. Here's everything you need to know about the quest, including how to find Cipher Qubits and Cloud Accretions.

Unfinished Business quest

　　The Unfinished Business Exotic quest from NimbusThe third step asks you to collect Cipher Qubits that drop from defeated Vex and extract five resources. These resources are shiny crystal shards called Cloud Accretion that are basically Neomuna’s destination material--adding the resource detector mod on your Ghost helps find them. You’ll need eight Cipher Qubits to extract Rohan’s data from each Cloud Accretion.

　　Collecting Cloud Accretion materials on NeomunaAfterward, head to Maya’s Retreat through the glittery caves of Límíng Harbor until you reach a beachside area with a Vex conflux. Recovering the data packet triggers small waves of Vex to spawn. Once defeated, collect the data and visit Nimbus and Osiris at the Radiosonde--a tunnel-like building near Límíng Harbor filled with Vex. Head through the doors and defeat enemies to reach Nimbus and Osiris at the end.

　　With new information coming to light from their conversation, you’ll have to play through the Thrilladrome Lost Sector in Límíng Harbor to retrieve a Vex compass found in the final chest. This Lost Sector is a bit hard to find, but when you reach the marked destination on the map, jump onto the upper platform inside the building and make your way down the vent. The first part of this Lost Sector has Vex crowd a tight space, but you would benefit from medium to long-range weapons and a barrier-piercing weapon for the boss fight.

　　Then make your way to the next destination to draw out and defeat 100 Shadow Legion combatants, which goes by quickly if you can participate in the Terminal Overload public event. Then head inside the Typhon Imperator--if you have the quest marked, it will show you where to go. When you arrive at the massive circular room from the Downfall campaign mission, defeat the Cabal at the center of the arena, then jump onto the platforms on the sides and collect the Seed of Silver Wings--they look like jars on a shelf. Complete the objective and go to Nimbus.

　　The Typhon Imperator room for the Seed of Silver WingsNimbus will give you Rohan’s Passkey, which sits in a Power weapon slot, and head to the What Remains mission flag marked on your map.

What Remains Exotic mission

　　The reflective mechanic in the What Remains Exotic missionAfter you pass the Taken enemies, you should reach an area called Embrace to acquire Deterministic Chaos, but the mission doesn’t end there! Continue down the path and try out your new weapon against the enemies, defeating the Conceptual Mind Hydra boss.

　　Complete the Unfinished Business quest by visiting Nimbus and the Hall of Heroes.