Just as Weaver is being more of a weirdo than usual and Ben is jumping rope for nearly three hours straight, Porter visits with the news that Skitters in Boston and all over the country have been converging on their big, looming structures. In four days, there's going to be a coordinated attack to try to bring those structures down. They're taking the war to the Skitters! Good luck with that, humans.

Meanwhile, Pope apparently has some expertise in blowing shit up and so is assigned to work in the explosives lab with a reluctant Uncle Scott, who hasn't been doing such a bang-up job with the bomb building. Scott has been dissecting a Mech to try to figure out what makes it so effective, and accidentally shoots a Mech laser hole in the wall. At this point, Pope quite sensibly offers to take over. Meanwhile, Rick gives Weaver a drawing of row houses and Weaver freaks out. Later he takes his mysterious pills on a couch, and his hat is off. It's like seeing Bret Michaels without a bandana -- so weird! Weaver actually might be slightly ginger on top.

Tom starts talking to the others about how weird Weaver has been acting, and Weaver catches him. Tom notes that Weaver hasn't been consistently making the best decisions and, to wit, Weaver says that he's going to replace Dai on their scouting mission to the big Skitter structure. He apparently had a construction business, and says that knowing where to hit the structure is as important as how. Meanwhile, Ben goes to see Anne for a checkup and asks if his nubs are going away yet. Anne pokes at the hardening skin around the nubs, and Ben doesn't feel a thing. She looks concerned about this, but she doesn't yet say why or even tell Ben about it. Instead, she goads Ben into talking with Rick, who is still acting quite strange.

At the Boston scouting mission, Weaver notes that the big structure is made of earth materials -- the copper wires and such that the harnessed kids have been collecting -- using basic construction techniques. He's certain that if they get close enough, they can topple it. But then! They see Skitters working and talking to yet another kind of Giacometti-looking stretched out humanoid alien! No one has seen these bastards before, and Tom thinks they might be commanders of some sort. On their way out of the city, Weaver, Tom and Hal run into a cranky lady with a gun named Sonja, who says she never left the city and is living in an apartment next to the Skitter structure. Hal and Tom take her up on her offer to pay a visit while Weaver volunteers to stand guard.

Little Matt defies his orders from Tom to stay away from Pope, and visits the bomb lab. There he learns that Pope learned so much about making explosives in jail. Matt is curious about the Mech parts, but also afraid, and Pope tells him that they're just piles of junk. He puts out that Mech bullets, in fact, use casings from human bullets that they've stolen/recycled, but the slug is made out of some sort of nasty and super-potent Mech metal that can be shot through people, walls, cars, whatever. Matt says he wishes that we could use their fancy bullets against them, and Pope has an Oprah-certified aha moment.

Ben talks to Rick as the other people in the Second Mass look at them suspiciously. And, it turns out, with good reason. Rick says that the doctors may have removed their harnesses, but that doesn't mean that "they've" abandoned them. He thinks they're lucky, but Ben hates the Skitters and wants to kill them. Rick counters by saying that the Skitters love them and will come back. That doesn't sound promising, does it?

Meanwhile, crazy lady Sonja serves Hal and Ben tea from a lovely china set, and they wonder how she has so much nice stuff and food. She says that the aliens took her away to a camp for a while, and then let her go because they don't care about someone like her. At this camp, she had an opportunity to talk to the aliens through the harnessed kids. She says with certainty that they don't want any human people on the planet. Just as things are getting juicy, Hal and Tom hear a motorcycle -- it turns out that Weaver has taken off and also pulled the spark plugs on their bikes. They take a minute to get them started again, and Sonja seems sad that they're leaving.

Back at the Second Mass, Anne and Lourdes vivisect the remains of Hermie. They find muscles, bones, a circulatory system and, deep down, a HARNESS! Yes, people, these Skitters were possibly something else -- like, say a human kid -- at some point. It's madness! Anne doesn't want to tell everyone about this, because they're freaked out enough about Ben and Rick as it is, but agrees with Lourdes that they at least need to tell Tom.

Hal and Tom find Weaver at his old house, where he's drinking whiskey and looking at his old grill. He tells Tom that he and his wife split a year before the Skitter attack, and then gets all freaked out afresh at the fact that Rick drew a row house that looks much like his own. He wonders if Skitters are planting things inside of his head to get to him. Tom tries to deflect this weirdness by asking Weaver what's up with the blood that's inside the house, and learns that Weaver captured his harnessed daughter and tried to conduct de-harnessing surgery in his kitchen. That didn't work out so well. Weaver has been living on revenge, but says that it's not good enough. He's ready to quit the mission and sleep in his own bed for a change. And then a Mech attacks. At first Weaver wants Hal and Tom to leave him, but then he sees his ex-wife's glasses on the floor and changes his tune. He pops into action, they kill the Mech, and then realize that crazy Sonja probably gave them up.

We're then back in Sonja's apartment with the three men and learn this is true. A visitor comes to her door to get information. It turns out it's harnessed Karen! She leaves food after confirming that Sonja has no new info to give them, and then the big lanky humanoid alien tries to look through the peephole. Tom, Hal and Weaver take their leave, giving Sonja the wrong information about their future whereabouts as a precaution.

Tom does Weaver a solid by not telling Porter about Weaver's momentary lapse of commitment in their report-out. Weaver tells Tom that he changed his mind when he saw his ex-wife's glasses because they weren't there when he last left this house -- there's a chance that she's still alive. Meanwhile, Pope has a bullet demo to show to the entire Second Mass. It turns out he's figured out how to make a Mech bullet, and there is a giant cheer as he shoots it clean through a decapitated Mech head. The only one not cheering is Rick, who conspicuously leaves. Weaver smiles as he says that they're taking the fight to the aliens. Let's hope that Rick doesn't ruin everything!