Marvel's Eternals Theory: Captain America Is The Reason Eternals Haven't Intervened In MCU Events Eternals trailer has a lot of hints about that answer, and those clues have led us to theory: Steve Rogers/Captain America is the reason why the Eternals have been absent in the MCU through Phases 1-3 - including the Battle of New York and Thanos' Snap with the Infinity Gauntlet. The theory is a bit more involved than that (as you can see below), but there are already too many connections between Captain America and the Eternals to ignore. One of the major Easter eggs in the