Agent Dale Cooper and Sheriff Harry Truman discover more about the troubled secret life of the murdered Laura Palmer.
My guess is that the father of that girl, who started dating the biker, the friend of Laura, he’s the murderer. For his daughter’s wellbeing, or shit like that.
Also, we’re given the suspicious info on that abuser, who beats his wife.
The daugher of the hotel owner, it looks like she’s just eager to fuck the FBI detective.