Fire bursts from the blackness, so much higher and hotter than I imagined, blowing my hair back and singeing my cheeks. It races down the barge like a hurricane wind, wild and free, making popping sounds that are louder than gunshots.

The wildfire reaches the propane tanks. Nothing happens.

The walkers press forward again, skirting the fire by staying to the edge of the barge, as far from the burning troughs as they can get. My heart sinks. I just blew our one chance to take down the tower in order to kill these things, and it didn’t even work.

The dragonfly is nearly upon me, its nose skimming over the heads of the walkers.

The propane tanks explode, jerking the barge violently. My eardrums feel like they’re bursting as a massive fireball boulders into the air. The walkers’ mouths open in silent screams as the fire takes them, disintegrates them to nothing.

A chunk of shrapnel wings my way, and I barely duck in time to avoid it—as the fireball engulfs the dragonfly. The drone teeters in the air, its silvery hull turning red orange like the sun. Its sides begin to slip away, molten and dripping, until it loses control completely and drops like a stone, disappearing into the waters of Lake Erie.

I have no time for relief, because the end of the barge is drowning, sinking lower and lower, and it’s going to drag the tugboat with it into the depths. I have to get Wyatt and Emmaline off this thing fast.

I sprint for the rowboat, which hangs alongside the first deck by chains on a pulley. But my feet feel heavier than lead and my heart is a stone. I’ve failed so utterly. I may have saved us temporarily, but that tower will keep rising every day, keep pouring methane into our atmosphere, and a few years from now, the full invading force will arrive and the earth as we know it will cease to exist.

I reach the rowboat as Tanq and Trey round the stern of the tow. I grab for the pulley, and I’m about to shout for Emmaline to come, but suddenly Trey is gesturing wildly from his spot behind Tanq on the Jet Ski.

“Keep going!” he shouts, pointing to the tower. “It could still work!”

I gape at him. The coal barge is sinking. It will be underwater soon, if the fire from the coal troughs doesn’t get it first.

“Keep going!” he repeats.

I have no idea what he’s thinking, but Trey is the smartest of all of us, and I’ve no doubt he understands something I don’t. I sprint back to the bridge cabin. Emmaline is crouched behind the captain’s seat, trembling, tail tucked as far between her legs as it will go. “Oh, Emmy, I’m so sorry, but I don’t have time to comfort you now.”