Seems oddly derivative of "Babylon Berlin"

Even though the historical era is different.

1) Earnest but over-her-head female police officer
2) Scheming Russians
3) Cop searching for his missing brother who is in fact a kind of madman mastermind
4) Various underworld figures and their weird conspiracies
5) Climate of little moral standards and widespread moral transgression (prostitution, rape, etc)

Though so far no obvious Nazis, although I'm maybe on episode 3.

I like it anyway so far, although the Brooklyn cop angle seems overplayed as a stylistic element, and Michael C. Hall's thinly veiled homosexuality is too transparent by more than half, as is his figurehead British wife's sexually adventurous personality and the predictable angle she is engaging in selling out secrets as part of some revenge.