Star Trek: Discovery wrapped up its first season on CBS last month with the 15th episode titled "Will You Take My Hand?" In this episode, the Mirror Georgiou (Michelle Yeoh) is alive in the main universe and goes off to wherever Mirror people go to. However, an unused bonus scene shown at WonderCon this weekend followed Mirror Georgiou to an encounter with a Trill who is actually a human in disguise, writes i09. After a short conversation, the Trill/human presents Mirror Georgiou with a black badge, saying, “Welcome to Section 31.”
According to i09, this confirms one of Season 1's mysteries: The identities of the black badge-wearing officers aboard the Discovery, who were actually agents of Section 31. First introduced in Star Trek: Deep Space Nine, Section 31 is Star Fleet's black-ops division that officially doesn't exist, sort of like Scandal's B613. Since they're off the grid and autonomous, Section 31 can carry out all kinds of covert operations (some of them not so nice like assasinations), all in the name of protecting Star Fleet and the United Federation of Planets. The orginization popped up again in Star Trek: Enterprise and then in Star Trek: Into Darkness.
It will be interesting to see what part Section 31 plays in further seasons, but given their penchant for secrecy and subterfuge, it probably won't be good for the crew of the Discovery, particularly if Mirror Georgiou will be joining their ranks. 31 can do whatever the hell it wants, whenever the hell it wants, so get ready for some major violations of those sacred Star Fleet orders. Its very existence makes Star Fleet almost pointless in a way, which is a very cool conept for the Star Trek franchise.