Four universes, one spine each. Events sit in narrative order; a date appears only where a source gives one.
The original continuity: Group 935, Element 115, and a time loop Primis Nikolai finally breaks at Tag der Toten. The only universe with an official ordering artifact, the timeline poster Treyarch shipped with Zombies Chronicles. No events charted yet.
BO4's parallel storyline: the Order, the Sentinel Trials, and Scarlett Rhodes's crew chasing her father from the Titanic to Delphi. The arc ends unfinished after Ancient Evil. No events charted yet.
Unrelated to Vanguard's Dark Aether, which shares the name only.
Cold War, 1980s
CIA-backed Requiem, directed by an unseen Edward Richtofen, races the Soviet Omega Group across Dark Aether outbreak zones.
Die Maschine · Firebase Z · Mauer der Toten
1985
Requiem defeats the Forsaken. Samantha Maxis seals the dimension from the inside.
Forsaken
1985
Project Director Edward Richtofen has Requiem's senior staff, Weaver, Grey, Carver and Strauss, imprisoned without trial.
Forsaken · Terminus
1986 – 1991
At the Terminus Island blacksite, Dr. Revati Modi weaponizes Aetherium for Richtofen's private agenda. Human experiments included.
Terminus
Feb 19, 1991
Smuggler Maya Aguinaldo frees the imprisoned Requiem crew with William Peck in tow, as a Dark Aether outbreak swallows the island.
Terminus
Feb 18, 1991
The same night, an outbreak erupts in Liberty Falls, West Virginia. The other half of BO6's opening.
Liberty Falls
Feb 1991
The crew disarms the warheads Modi rigged to level the island, then destroys Patient 13, a Janus scientist mutated into a kraken-scale monster, and exfils to hunt Richtofen.
Terminus
1991 onward
Requiem's survivors pursue Richtofen through the rest of the BO6 arc.
Citadelle des Morts · The Tomb · Shattered Veil · Reckoning
Nothing in the Cold War–BO6 arc references it; treated here as its own universe.
Officially billed as a prequel chapter of the Dark Aether saga, but its story is self-contained: WWII, Kortifex the Deathless, and entities bound to artifacts. Four maps, concluded in The Archon. No events charted yet.