Résumé: This is what the Watcher has been watching for! A danger older than the Earth threatens everything. For once, the heroes who have saved the planet so many times are almost powerless in the face of it. X-Men and Avengers assemble. Spider-People and Fantastic Four come together. Heroes for Hire fight alongside Champions. None of it will be enough. The lights are about to go out. The world outside our window...is about to end.