In some ways, this was one of the less-distinctive, more X-Files-ish episodes of Fringe on Thursday night. The core case investigated by Olivia, Peter, and Walter involved people committing violent acts — they saw everyone around them as demons, and lashed out at the creatures (who were just innocent bystanders).

But as usual, there was another narrative layer at work here, a couple of them, in fact. One involved Olivia: She was still mourning the death of Charlie — or rather, her killing of “Charlie,” the shape-shifted version of her friend and colleague. She received more helpful, if obtuse, advice from the poker-faced bowling-alley savant Sam Weiss.

The other involved Walter’s past experiments mingled with his early parenting of Peter. (Peter told us that when he was a kid plagued by nightmares, Walter taught him an effective mantra: “Please don’t dream tonight.”)

The essence of the episode circled back to Walter’s past. SPOILER ALERT. The violent delusionals in this episode (which was entitled “Dream Logic”) were the patients of a scientist-doctor working on sleep disorders. Turns out he was experimenting with “stealing dreams,” and as Walter put it, “siphoning them off before consciousness.” The doctor became addicted to filling his own head with these visions — in a sense, downloading them into his own brain. Walter proved it by reproducing some of these effects by dumping similar data into his own brain, back in his lab.

Why’d the scientist force his patients to do these things? For a reason Walter knows all too well from his 1960s work: “For the rush,” said Walter — the rush of an addict. Comparisons were made to taking LSD or mescaline. Once again, Walter’s counterculture-era experiments ended up influencing his present-day life. I can’t help but believe that this repeated Fringe theme is going to pay off big-time down the line.

Did you watch Fringe this week? What did you think?