Turned out dream bubbles were as mortal as their occupants. They began to decay. With the decay came recollections, and everyone began gruesomely flickering between their corpses and their imagined selves.
The first time it happened to Eridan, he panicked. He had seen it twice before, first time as a startled bystander and the second as a caretaker plus shoulder to cry on. He had known would happen to him eventually, but it had been as far off a thought as death had been when he was alive. And, like death, the recall caught him by surprise in the worst possible way.