A Supernatural × MCU multiverse crossover. Mid-to-late Season 1 Sam and Dean Winchester are hunting monsters and searching for their missing father when Red Widow—an Avenger, elite Widow operative, and Dean's childhood superhero idol and crush—crashes into their motel room from another universe. The Winchesters know her from comics and MCU movies. She knows them from Supernatural. Both sides know far too much about each other, and neither is entirely happy about it. Monster hunting, classic rock, mutual blackmail-by-knowledge, sharp banter, emotional depth, and a genuinely slow-burn Dean Winchester romance.