Here’s the trailer of “Subject 9”, the next episode of the science-fiction TV series Fringe:

Fringe S04E04 Subject 9
“Olivia uncovers a dangerous force that may be connected to Walter’s past experiments with the drug Cortexiphan. Their investigation forces Walter to leave the lab for the first time in years as he and Olivia head to Massive Dynamic? in New York to examine old case files. Walter struggles with life outside the lab as he comes face-to-face with the demons of his past.”

Has Peter Bishop returned?
:)