Today, millions across Spain and Portugal have found themselves plunged into darkness. An unprecedented blackout has swept the entire Iberian Peninsula. Subway trains ground to a halt in Madrid and Lisbon, traffic lights blinked out, flights were grounded, and hospitals scrambled to keep critical systems running on backup power. Daily life has been paralyzed, the Spanish government has declared a state of emergency, and the cause of the outage, for now, remains a mystery.