It's not like these two have ever been real pals, although we did gain some insight that they used to be partners.
And the shady past for most of the characters on Low Winter Sun continued to plague their present selves and actions.
It's obvious that Frank is good at what he does, an over 70 percent success rate as a cop calls to that. He's cool under pressure on the stand, he can clearly commit a murder and (so far) get away with it, and he knows how to rip a tooth right out of someone's mouth. It's just too bad that he can't be there to protect Katia.
Because, really, that was