Fringe (2008)

S4E4 Subject 9

In "Subject 9," Olivia stumbles upon a perilous entity linked to previous Cortexiphan experiments. This revelation compels Walter to venture out of the lab for the first time in years, prompting a trip to Massive Dynamic to review archived case files. As he delves into this investigation, Walter grapples with his emotional turmoil, facing the haunting memories from his past that resurface during the journey.