DEAR LORD WHAT IS THIS SHOW DOING TO ME! It's amazing. Every episode of this season just keeps getting better and better. I'll try and restrain my enthusiasm long enough to get out a plot summary.
So Logan Sanders decides that the best way to take out Mike and Walter Gillis is to dig up personal dirt on Mike. Harvey protests, but Logan says if Harvey doesn't do it, he will. Harvey is stuck - Donna tells him to get Mike to quit, but Harvey knows that he won't. So, feeling terrible about it, Harvey goes to Gillis and tells him about Mike's past with drugs. Apparently, Gillis' son's death had something to do with drugs. Gillis immediately severs ties with Mike.
Mike confronts Harvey about it, and when Harvey insists that he was saving Mike, Mike reveals that he has Harvey's father's records, something that Donna told Mike Harvey was trying to procure. Logan Sanders still isn't happy. He wants Mike utterly destroyed. Harvey wants to go ask Mike to give up, but Donna suggests that he have Rachel do it instead. Rachel doesn't go to Mike. Instead, she goes to Logan and convinces him to stop the personal attacks on Mike. Logan owes Rachel because of something that happened in their past. Logan agrees, and backs off. Mike sends Harvey's dad's records to Harvey, via Rachel.