Of course, Broyles does understand that, but the longer they wait, the more likely other innocent people will be killed. "He'll die! Do you hear me?" yells Walter, pounding the table. And in case you're not clear why he's taking this so hard, he says, "You're going to kill Peter!" Olivia corrects him -- Walter of course doesn't realize he said "Peter" -- and Broyles says Walter's got two hours -- or until there are any more attacks.
Time for Walter to kick it into high gear. He tells Astrid they need to reconfigure the neurostimulator for magnetic resonance to chart Aaron's brain activity. I was just going to say! Meanwhile, Broyles orders Dunham and Lee to be ready to move out: "Flamethrowers aren't going to be enough. We're gonna need some help." Something more awesome than flamethrowers? SO EXCITED.
Anyway, more than an hour later, the Fringe folks are walking through the park, with Broyles saying they've determined the fungus has encroached on at least a dozen populated buildings, all of which have been evacuated. Lee wants to know what the plan is to kill Gus (Broyles had not yet heard Walter's name for the thing), and that's when the Massive Dynamic cavalry runs to the rescue. Jeez, completely forgot about Massive Dynamic! Guess Walter doesn't run the show anymore. I guess it would be difficult to do that from his Harvard lab bedroom. Plus, in all those polished surfaces in Massive Dynamic's shiny facility would have Peter all over the place.
"You two, along with one of their techs, will be administering a potent toxin to the fungus," says Broyles. Oh, "one of their techs," is it? Broyles may as well identify the tech's next of kin right now.
Olivia checks in with Walter, who has managed to isolate Gus's brain wave within Aaron and determine the link appears to be centered somewhere inside Aaron's prefrontal lobe. But that doesn't mean he knows how to disconnect it yet. "My attempts to shut down that part of his brain haven't worked," he says, which means there's only one other option: "Surgically remove the infected part." Olivia flips that he's considering lobotomizing a ten-year-old: "You're gonna find another way, and I'm gonna talk to Broyles, explain the situation to him, and see if I can buy us some time," she says.
Time is what they don't have, because Broyles comes up to say the fungus has reached a subway platform in midtown, and they have to move on it now. Over Olivia's protests -- and I'd like to know if Olivia would prefer to break the news to the families of people killed by the fungus -- Broyles says, "I'm sorry, but you know as well as I do we can't sacrifice countless other lives to save one boy."