Hysteria seizes the lobby. Only a few of us know about the charges, but anyone can look at Oleg's industrial-grade padlock and recognize bad intentions. Jared and Minosh grip the inner door handles, heaving, leaning to no avail.

A random salesman is shouting about breach of contract—"You said forty hours, not one minute more!"

"Break a window!" I yell myself. I try hoisting the pub-style table in front of me, but it's bolted down.

Susan directs other efforts, marshaling small teams, calling out particular windows to target. Carter struggles under one corner of a loveseat. Prisha dumps apples off a porcelain platter and slings the platter discus-like at the glass-which bows and thunks and trembles in its frame, but won't break.

"Paul!" I say. "You know some EE, right?"

He is grinding two knuckles into a crack of a south window, but the crack isn't getting bigger. "I—well, yes, I minored electrical at Carnegie."

"Let's go, come on!" I plow through the roiling crowd to pull him away. "I saw the trigger—I know where they put the trigger!"

Cursing myself for not disabling the charges when I had the chance—when I had time—I race upstairs to Ten. I grab wire cutters from Security Kyle on the way, ripping open his toolbox, upending nails and nuts and stud finders. Paul hustles after.

We zoom through E-wing to the workspace of Omar Mohammed.

How many minutes do I have? How many seconds?

I have no idea. Oleg doesn't know I know about the charges—assuming again Graham didn't sell me out—so maybe he'll wait, make some progress on his getaway before blasting this place into a tomb.

Or maybe he won't. Maybe having slapped on the mega padlock, he'll figure we're going to try escaping immediately and jump onto his metaphorical bomb plunger the instant they round the corner.

Omar left behind a windbreaker, the blue Cisco logo sagging off his chair back. I motor into his cubicle and dive underneath his workspace counter to the baseboard. Two wires run here from a small hole in the ceiling, of which I saw the other side earlier. Somebody has stapled the wires flush to the wall and painted them over white—a slapdash job, but nothing you'd notice at a glance.

Here at the baseboard, connected to the wires, is a metal box sized like a lunch pail. It has a single indicator light along its top edge, which currently shows solid green.

The detonator.

And up in the ducts, the bang-bang.

Separate detonator from bang-bang, problem solved.

I spread the jaws of my wire cutters and slip one between wall and wire, separating the two, breaking a thin coat of freshly dried paint. I'm about to squeeze the handles and snip before second thoughts come.

Maybe it's less simple.

Maybe what sounds infallible inside your brain is actually...fallible.

Footsteps pound nearer. I decide to wait for them before snipping. In the meantime, I stare at the detonator, willing it not to change state or otherwise bring three floors crashing down onto my head.

Paul lunges into the cubicle, clutching his side.

I begin, breakneck, "Here is the detonator"—pointing to the box—"and there're the explosives"—now to the ceiling—"and eight or nine floors have 'em up in the ducts, all networked together wirelessly. I was going to snip both wires to take the detonator off the circuit."

He tips his flushed face one way, then the other. "Probably that will work. Unless they wired in a brownout circuit closer to the charges."

"Brownout?"

As precious seconds tick away and indeterminate cries sound from the lobby, Paul quickly explains you can plug a small power source into a larger circuit and wire it such that the system is fail-open (instead of fail-closed or fail-safe), meaning a break in the main circuit will trigger the positive case.

I.e., the explosion.

"The only reason you'd bother," he concludes, "is if you were worried about sabotage. If you were exercising extreme caution."

I pull the wire cutters back another inch. "At least one member of their team is operating under duress. And Oleg does not have a nature I would describe as incautious."

Paul sighs in agreement. "Did the charge on this floor look different? Was the mechanism the same size as other floors'?"

I squinch my face, trying to visualize, but right now all the duct scenes are running together in my brain. "Eh, it'd be a pure guess."

We strain to move a table under the nearest HVAC vent, and one last time, I hurl my body up into that dark, dusty, stifling tunnel. With Paul instructing me through the ceiling, I push Hedgehog Eleanor Roosevelt and her still-kicking flashlight ahead.

I find the charge. It does have a small additional mechanism—round like a smoke detector, right beside the hole in the ceiling.

"That'll be a 'yes' on brownout circuit," I call down. "Want me to crack it open?"

Paul shouts back sure, but how about twisting rather of cracking? I do twist, and the top half lifts right off.

This circuitry, which I keep having to prop Hedgehog Eleanor Roosevelt's screen at different orientations to see, contains half a dozen wires sticking out of a simple five-dollar breadboard, with a nine-volt battery for a power source. It looks like something a kid put together at Radio Shack while her dad was ogling speakers.

I ask, "Can I just pop out the battery?"

"They could've wired to fail-open here too," Paul says. "How many transistors do you see?"

I count. "Seven."

He doesn't answer straightaway.

I yell, "What? What does seven tell you?"

His voice returns, "Could be fail-open. A simple brownout circuit wouldn't require more than two or three transistors."

Fantastic.

In a parallel mental process, I'm figuring how far away Oleg has gotten—how long we might have. Will he wait until his brigade of vans has crossed the Bay Bridge? Or until they're out of SanFran proper and nearer the airport?

Would the FAA ground planes for an explosion of this size?

"So...what, now we have to disable both power sources simultaneously?"

"That's correct," he calls up. "You left the wire cutters down here—lemme go grab them."

There are scrabbling sounds, then more footsteps—but different, crisper than Paul's.

My stomach drops as I think for a second Elite has discovered our rebellion...then remember they already took off.

The voice is Susan's. "Deb? Deb, where are you? We're trying but we can't break the glass—"

"I got this," I yell. "We got it—we're doing it. Just stay back!"

She gives no verbal answer, and I imagine her closing those long eyelashes and biting her lip, chastened by this fiasco that's taken place on her watch. But who the hell knows? At this point, I have no claim on what lives inside anyone.

"Paul!" I call down. "On three, yeah?"

He answers, "On three!"

I poise my fingers at either side of the nine-volt battery. I bring my face so close I can see my own breath condensing on the terminals.

Sweat drips down my neck. I lie flat against the duct bottom, my heart beating against cold steel.

I start, "One!"

Paul follows, "Two!"

I rock between my elbows, ensuring my grip on the battery and its connector.

Together, we say, "Three!" and I jerk my battery free at the exact moment that Paul—I hope—is clipping his wire.