10 Star Trek Storylines Begging To Be Continued

So far in Star Trek, the Breen have never removed their helmets on-screen. There are some characters who must know what they look like - both Gul Dukat and Colonel Kira 'sourced' Breen uniforms, but neither ever described what they found.

Beta canon actually explains a little about the Breen. Zero Sum Game, by David Mack, reveals that the Breen are not entirely the same. In fact, they are something of a cooperative of differing races and species, wearing these uniforms to hide their differences. This would make them, at least in part, like the Xindi. While the Xindi don't mask their differences, there are five separate races (six if you count the extinct Avians).

Other than this Beta canon reveal, next to nothing is known about the Breen. Who are they, really? Why did they side with the Dominion during the war? Chancellor Martok reveals that a fleet of Klingon ships was once sent to invade their homeworld, and never returned. There has been enough intrigue with these mysterious warriors that a deeper dive into their origins, or organisational structure, would be fascinating.

By the 32nd Century, what does the Breen Confederacy look like? Do they still hide their appearances, or have they learned to live in the light? And just what the hell does all of that shrill barking actually mean?