A "White Event" creates four superhumans who are meant to lead to the next stage of human evolution yadda yadda yadda. There have been previous White Events, though, and the last one had two of the superhumans pair up and conceive a child -- whereupon the NSA decided to kill them all to prevent humans from becoming obsolete.
This was an attempt to do a new Marvel continuity with many fewer ties to the traditional comicsverse -- occasionally names you know are mentioned, but they're never major and their lives don't hew closely to the lives of their counterparts. (In 1954, Tony Stark escapes from capitivity in Korea in a flying robot suit. Then an NSA assassin verifies that his superengineering powers are the result of a White Event and shoots him in the head.)
This is intriguing and got cancelled after six issues in the middle of a storyline. There's a single-issue story that depicts a White Event in pre-history (boring) and a single-issue story that depicts the White Event in the 50s that created the current NSA protocol (neat). Probably too frustrating to be worth it, unless you're interested in how it instersects with Jonathan Hickman's Avengers (I am).