Humans and Watermelons Alike Explode on Fringe

Last night's Fringe started out with unusual bang, in the form of a literal human bomb. Soon the Fringe team is blowing up watermelons, traveling to Iraq, and reminiscing about Peter's childhood Playboy jigsaw puzzle. Spoilers ahead.

Initially, it looked like we were getting another stand-alone episode this week, involving a police officer who mysteriously crystallizes and explodes upon touching a nondescript briefcase, taking out the briefcase and everyone around him. While Walter and Astrid are putting Humpty Dumpty back together again, they discover that the exploded cop was injecting himself with something that likely turned him into a bomb. When Peter realizes the cop must have been injecting the serum as far back as his tour in Iraq, he heads off to Baghdad with a physically and cognitively unstable Olivia in tow.

We're probably meant to assume that, because this serum (known as "Tin Man") came to Iraq and happens to make people explode in very public places, Iraqi scientists were actively trying to turn people in human bombs. But no, no. The Iraqi scientist who created it had pretty unambiguously benevolent motives. He was trying to counteract the effects of a neurotoxin several of the soldiers were exposed to, and it just happened to make most of them explode. Bummer. And, if anyone is going around making soldiers explode, it's the psychotic colonel who was attached to the Tin Man project.

By using the serum to blow up a watermelon (prompting the ever put-upon Astrid to ban fruit from the lab), Walter is able to determine that a certain frequency is triggering the explosions, and by emitting a counter-frequency, the explosion can be prevented. Sure enough, the team manages to locate another former soldier injected with Tin Man headed for another nondescript briefcase; the explosion is averted and the colonel is apprehended. Everyone lives happily ever after.

Ah, but then comes the big reveal. This was about so much more than exploding watermelons and jaunts abroad. It was about the briefcases. The briefcases belong to none other than the Observer, or apparently multiple Observers, who pass their surveillance back and forth via courier.

The Observer(s): So now we know there are multiple Observers, and that they're passing information amongst themselves. No great surprise there, as we've seen the Observer talking on the phone to someone before. But is their purpose really to destroy us, as the colonel seems to suggest? And is that our Observer getting the briefcase full of pictures of Walter? And is that actually our Walter, or could it be the Walter from the other universe?

Olivia's Guru: Kevin Corrigan, as Olivia's bowling alley guru, is trying to convince us he's the world's most boring cognitive therapist, trying to restore Olivia to her former self by making her score kiddie bowling and tie her shoes. When she's fed up with his Mr. Miyagi schtick, she pulls her gun on him. She's shocked she managed to walk without her cane, but I'm more concerned with her mental health, especially since she had vomit-inducing flashbacks earlier in the episode and it looks like next week the floodgates are going to tumble open.

A Little Bit of Astrid: She's still cleaning up Walter's messes, but it's nice to see Astrid say something to Walter and have him actually hear what she's saying. When Walter is predictably resistant to Peter finding them a new place to live, it's Astrid who very gently nudges him in the right direction. Plus, Walter even managed to acknowledge that he never shows any interest in Astrid's life beyond her cleaning and culinary abilities. Maybe now we can finally see her in the field?

Walter Moment of the Week: There are so many to choose from here. Aside from the thing with the watermelon, we learned that Walter had Peter assemble a Playboy jigsaw puzzle when he was ten as a sort of misguided anatomy lesson. But the best moment comes when Walter asks Peter to be a little more considerate of Gene: