In an alternate universe set in the year 1602, Captain Peggy Carter is summoned by that world's Scarlet Witch to help prevent the reality from collapsing in on itself. She arrives to find familiar heroes and villains transplanted into the early 17th century, serving under Queen Hela... until a rift tears open and pulls Hela through it, leaving Carter blamed by Thor and declared a fugitive...

In a radical departure from the established chronology of the Marvel Cinematic Universe, the destruction of Asgard during a premature Ragnarök forces the Tesseract from its ancestral vault and onto a collision course with Earth centuries before the modern era. Rather than being safely recovered by Norse worshippers in Tønsberg, the artifact settles at the bottom of a lake in the territory of the Haudenosaunee Confederacy in pre-colonial North America...