Fringe taught viewers about quantum entanglements on its latest episode.

Looking ahead, it will take fans back in time on "Subject 13." Next Friday, we'll watch Walter in action, six months after young Peter was saved from the lake. Events from his life will be examined, secrets from Olivia's past will be revealed and this Fringe character will have a lot more hair than he does now.

Check out the following preview and sneak peek at the installment now:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.