When my vision clears, I count two more down. Maybe three. But they're learning. Adjusting their tactics. The next assault will be smarter.
"I'm down to one magazine," Willa says quietly.
"Make it count." I'm on my last two. We've held them for maybe ten minutes. Twenty more until backup arrives.
If backup arrives. If Tommy realized we're in trouble. If Stryker and Mercer can reach us in time.
A lot of ifs.
The tunnel goes quiet. No movement. No sound except our breathing and Odin's low growl. The dog's still alert, still detecting something.
"They're regrouping," I say. "Planning something bigger."
"Or they're calling in reinforcements."
"Probably both." I check my tactical display again. Still no signal. We're blind, deaf, and running out of ammunition. "We might need to fall back to the collapse zone."
"And then?"
"And then we trigger it. Seal the tunnel. Buy ourselves time until...”
Odin's bark cuts me off. Not the warning bay. The alert signal. Chemical weapons detected.
"They're going to gas us out," Willa realizes. "They've got nerve agent and they're going to flood the tunnel."
The implications hit like a sledgehammer. We can hold this position indefinitely against bullets. But nerve agent? We've got no protective equipment, no gas masks, no countermeasures.
We've got maybe three minutes once they deploy it before we're both convulsing on the tunnel floor.
"New plan," I say, already moving. "We trigger the collapse now. Seal them out before they can deploy the agent."
"What if backup can't reach us?"
"Then we dig ourselves out or we die trying." I'm pulling det cord from my tactical vest, setting charges on the structural weak points I identified months ago. "Better than dying from nerve agent."
Willa doesn't argue. She's already covering the entrance while I work, her rifle steady despite knowing what's coming.
I'm placing the last charge when the canister rolls into view.
Small. Cylindrical. Releasing vapor that immediately makes my eyes water.
"Run!" I grab Willa, dragging her deeper into the tunnel. Odin follows, barking frantically. Behind us, I hear mercenaries advancing, confident we're about to be incapacitated.
Twenty meters. The charges I set are behind us now. The collapse zone ahead.
Ten meters. My lungs are burning. Willa's coughing, eyes streaming. We're both breathing the agent now.
Five meters. I hit the detonator.
The explosion is catastrophic. Shaped charges blow through support timbers, collapsing tons of rock behind us. The roar is deafening. The pressure wave throws us forward into darkness.
We land hard. I taste blood, feel ribs screaming. Willa's beside me, gasping, coughing, but moving. Alive.
The tunnel is sealed. We're trapped. But at least we're trapped without nerve agent slowly killing us.
"Kane." Willa's voice is rough. "My vest. Inside pocket. Atropine auto-injector. My father—he made me carry it. Said if I was going to work as a trauma nurse in one of the overseas bases, I probably needed chemical weapons countermeasures."
I find the injector with shaking hands. Three doses. Enough for all of us if the exposure wasn't too severe.