Continuity mistake: When Walter is using the hammer on the block of ice, the pattern that results is different when viewed from each side.
Fringe (2008)
1 mistake in 6B - chronological order
Starring: Joshua Jackson, John Noble, Anna Torv, Jasika Nicole
Olivia Dunham: I just want to go back to before.
Phillip Broyles: Dunham, I don't think you can.
The Arrival - S1-E4
Trivia: Michael Cerveris makes his first significant appearance in this episode as The Observer/Bald Man. However if you watch the series from the beginning, he makes fleeting appearances in every episode, sometimes on a tv screen.
Question: Why would Luke Dempsey be arrested along with his father? He had no idea what his father was doing, never aided him in any way and only found out the truth after catching him in the act.
Answer: He helped his father evade capture, impeding the investigation.