Mackey at last learns who killed Lem: The Shield

"The Shield" Season six, episode 6, continues the torrid pace of this extremely powerful cop drama that rises well above the expectations (my expectations) of the genre. In this episode, Mackey (Michael Chiklis) at last figures out that his partner/teammate Shane killed fellow teammate Lembrowski. Mackey is torn apart at the amazing betrayal by Shane - Mackey has threatened to kill whoever killed Lem but had no sense ever that it would be another copy - and also by the fact that he'd tortured and executed another man, Guardo, whom he thought had killed Lem. Tremendous, long confrontational scene between Mackey and Shane - and perhaps Mackey is disturbed by some of what Shane says, i.e., that he had to kill Lem because Lem would have broken and ratted them all out for a previous murder and many other dirty-cop crimes. Maybe part of Mackey agrees with that and understands it. Still, Shane drives away a marked man - how will they play this out in future episodes? Something odd developing between Mackey and the new guy on the team, Mackey's intended replacement. Are they bonding? I think not, that inevitably the force is not big enough for the two of them and they'll have to go man-to-man. Mackey angling to beat the forced retirement and stay on the job - which we know will happen. I know it's just a story, and there are certain conventions for telling the story within a 47-minute slot, but I'm always distrubed by how busy and eventful the detective's lives are - always three plot lines each episode, solving the gruesome crime of the day, pursuing Mackey's personal agenda (catching Lem's killer), and dealing with family/domestic crisis (though this theme is not dominant in The Shield).