Background: A potent spirit of trains and murder, the EL was a dark force in the city in the 30s and 40s. But supposedly Diana Coal helped destroy it.
But its presence leaked into the present from some alternate reality. Valkyrie saw it in her Awakening. She remembers Miguel telling her about it, something he no longer remembers. The alternate reality it lives in is dying, ruptured when Cicero rewrote reality. There strange versions of the people the cabal knows live and die. And the train runs on.
Now it has escaped and become part of the real world. Someday someone will need to deal with it.