It was a non-mythology episode of Fringe this week, with a dandy creature to grapple with and a Walter Bishop subplot that turned into the main plot.

The creature first: a multi-tentacled “parasitic worm,” as Walter termed it; the “Snakeheads” of the episode’s title — a number of them, in fact, used most effectively in the opening scenes, as dead bodies were found, each with a big, thick worm wiggling frantically out of his or her mouth. The corpses were Chinese nationals discovered washed ashore, and the case led to a Chinatown herbalist. He was played by Tzi Ma, a familiar face probably best known as Cheng Zi, the very naughty Chinese Consulate security director on 24.

As herbalist Ming Che, he was using a gland from the wiggly worms that secreted an immune-boosting enzyme. The case was pretty X-Files-ish, with scant use for Agent Olivia Dunham (although Anna Torv radiates a strong reassuring presence throughout). Peter, man of many unexpected talents (as is Josh Jackson, having by now fully invested the character with far more than sarcasm and devillishness), speaks impeccable Cantonese. There was finally more for the underrated Astrid to do, even if some of what she did was get attacked.

All the better, therefore, that what looked like a comic-relief motif initially — Walter trying what Peter called “self-actualization,” asserting himself more, getting out into the world by himself — proved to be the true heart of the hour.

At first it was amusing to see Walter in an ascot, talking with crisp authority, only to lose himself in Chinatown. But things became poignant quickly, as Walter used up the supply of change Peter had given him as bus money, making frantic calls from a pay phone to his son… except Walter couldn’t remember the number. Which Peter had put in Walter’s pocket for just this reason — Walter had forgotten that, too.

This Fringe was a reminder that, for as much as we chuckle at Walter’s references to the consciousness-altering drugs he’s taken over the years (he got a literal contact high when one of the worms bit him this night, too), he’s still a damaged soul, just a year out of the institution from which he was released at the start of the series. He spoke to Peter of his fierce desire “to live like a man, not a child.”

It was a touching moment — John Noble really plays the hell out of scenes like this, conveying Walter’s fears and timidity without allowing us to forget that Dr. Bishop is also a bristling genius. And the hour was capped off with a nice little joke. Admitting he was still dependent upon his son yet also wanting to continue venturing beyond his lab, Walter revealed to Peter that he’d implanted a tracking device into his own neck, so that his son could find him when he gets lost again.

Awww… Hey, next week: Looks like a big mythology episode! Can’t wait.

Did you watch Fringe this week?