In the newly revamped Blackrock Depths raid, players can earn the achievement A Dark Iron Past by finding temporal missives from Moira Thaurissan detailing the troubled history of the Dark Iron dwarves.
Alongside the updated boss mechanics and current-tier loot, each boss room on the path to Dagran Thaurissan has an orb situated nearby, which plays a message from present-day Moira Thaurissan showcasing her thoughts on the actions of her people back during vanilla WoW.
This missive can be found after defeating Lord Roccor, near the old entrance to the Detention Block.
This missive can be found at the initial entrance to the Dark Iron Highway, after defeating High Interrogator Gerstahn.
This missive can be found on the northwest side of the Dark Iron Highway, after defeating Bael'Gar.
This missive can be found at the entrance to Shadowforge City, just before reaching the Black Anvil after defeating Lord Incendius.
This missive can be found in the upper level of Shadowforge City, just to the right of the initial ramp next to the bridge.