The grey talon assassins are a very special group for one reason. They have never been caught. They are impossibly hard to find; many doubt their very existence. Once one has found them, they can be sure the job will be done… for the right price of course.
There is an important pair of fraternal twins. Possibly minor dieties, sorcerers, or maybe just an important pair of nobles. One is evil and one is good. The thing is, the one who looks evil at first glance is the good one, and vice versa.