On March 3, 2010, the group announced on their official separation of Bob Bryar, [26] who was for more than five years the drummer for the band. The group gave no explanation about his departure.
That same month, day 26, Mikey Way said the band's website that they have reached a "final phase of recording exciting." Gerard Way spoke about the recording process as "the second attempt from the album" because the former does not convince them.
On September 17, 2010 the band announced via a promotional trailer on its website the name of the new album, Danger days: the true lives of the Fabulous Killjoys, which was published in November. In the days following the announcement of a new world tour, which began in October in Europe, called World Tour Contamination. On Wednesday September 22 premiered on radio in the U.S. and UK the first single from Danger days, called "Na na na (na na na na na na na na na)." Days later published on the Internet a second song, "The only hope for me is you." On November 3 premiered on MySpace and on radio the single "Sing" and two days later was enabled free downloading of "Save yourself, I'll hold back Them."
All the songs on the album were made public for the first time on Tuesday 16 November, in a video shown on the website of the band. The songs are presented in a fictional radio show, hosted by the character Dr. Death Defying.