- Following the Illusive Man/ Anderson death scenes in the Citadel, the Crucible is activated but nothing happens.
- The phrase "Shepard-Commander" is heard and following a flash, the scene changes to Shepard standing in a digital world similar to Legion's ME3 mission
- Legion appears. Turns out that when he sacrificed himself to "go to" the Geth consensus on Rannoch, he wasn't able to fully transfer his data before the reapers stole his code
- Legion reveals that while he has been trapped in the digital!crucible he has discovered the plans for the crucible were actually planted by the reapers to provide a false hope to distract civilizations while they were harvested - the true purpose of the crucible is as a reaper weapon
- Legion suspects there may be a way to repurpose the crucible to destroy the reapers, and guides Shepard through the data nodes to achieve this
- Shepards memories appear as holograms throughout - important moments, character deaths, romance etc
The end goal is obviously that the crucible is repurposed to win the war and destroy the reapers (with varying levels of success or the difficulty of the "dungeon" dependent on war assets or previous actions in the game) but that's where my little daydream stopped. What a random thing to happen while I'm driving to work