Before the first pull
In non-encounter traversal, a visible bell may be shot through a grate to change which architecture is accessible. In encounters, bells are locked by Bellkeepers.
Supplementary dungeon tool
Duality interactive companion
Use this companion for encounter assignments, pull checklists, quick references, and fireteam planning. The complete written guide remains the main source for mechanics and detailed explanations.
Verified August 1, 2026Destiny 2DungeonAssignmentsGuide
Encounters
3
Team
1–3 Guardians
Guide checked
August 1, 2026
Planning
Saved per encounter
At-a-glance reference
Overview and downloads
Bell transitions
In non-encounter traversal, a visible bell may be shot through a grate to change which architecture is accessible. In encounters, bells are locked by Bellkeepers.
Bellkeepers
Bellkeepers are Cabal Incendiors tied to a bell.
Nightmare Collapsing
Encounter trips to the Nightmare realm begin with a 60-second lethal timer. Killing a correct Standard Bearer adds 15 seconds. In the Vault and Caiatl collection phases, killing an unrequested Standard Bearer sharply reduces the remaining time.
Downloadable guide
Complete Duality dungeon guide, checked August 1, 2026.
Dungeon tools
Pull checklist, assignments, and roster
Encounter route
Fireteam
Encounter 1 of 3
1. Defeat the Nightmare of Gahlran
Recover two Standards, deposit them to open two side rooms, enter Nightmare with players positioned inside those rooms, kill all Visions of Gahlran, damage the boss, and return before Nightmare Collapsing expires.
Roles assigned
0 / 3
Pull checks
0 / 5
Fireteam loaded
Manual planning
Role assignments
Assign from the loaded fireteam or type names manually. Plans save in this browser.
Left runner1 player(s) · 0 assignedCheck and collect requested Standard on left; clear left corridor Visions.
Right runner2 player(s) · 0 assignedCheck and collect requested Standard on right; clear right corridor Visions.
Bellkeeper / center3 player(s) · 0 assignedKill opposite-end Bellkeepers, open return bell, and clear center.
Pull checklist
0 / 51. Defeat the Nightmare of Gahlran quick reference
- Standard runners enter the two opened symbol doors. The Bellkeeper player stays in the main hall.
- Activate either available bell to return to Nightmare. The runners now occupy the two side corridors; the Bellkeeper player remains in center.
- Each corridor contains five Visions of Gahlran. Clear all ten. A corridor door opens only when its Visions are dead.
- The center player kills the opposite-end Bellkeepers and opens the return bell.
- When all Visions die, the main Gahlran becomes vulnerable. Runners converge into center and damage.
Encounter playbook
- 1Standard runners enter the two opened symbol doors. The Bellkeeper player stays in the main hall.
- 2Activate either available bell to return to Nightmare. The runners now occupy the two side corridors; the Bellkeeper player remains in center.
- 3Each corridor contains five Visions of Gahlran. Clear all ten. A corridor door opens only when its Visions are dead.
- 4The center player kills the opposite-end Bellkeepers and opens the return bell.
- 5When all Visions die, the main Gahlran becomes vulnerable. Runners converge into center and damage.
- 6At the escape call, stop damage and enter the active bell ring. Return to Material before the timer reaches zero.
- 7Repeat the full Standard and Vision cycle until Gahlran dies.