When Renraku needs to make something go away, they call on Sigma Squad, or at least on the team which has become known on the streets as Sigma Squad. This team of highly trained specialists have a legend which says they’ve done nearly everything but kill a Dragon. Of course, no telling how true that all is.
You are Sigma Squad, or at least your tattoos imply that you were. But how true or not your legends are is something you don’t even know. Since waking up at the scene of an accident, with the rest of your team, all you’ve been able to determine if you’ve got a Sigma Squad tattoo, and that the others in the area with the same tattoo feel trustworthy.