Gun Shells and shadows

Gone

I glance over my shoulder once again before following JJ down into the tunnels. The old subway tunnels are covered in graffiti so it's not hard to leave each other messages on the walls that other gangs won't understand or notice.
The shadows hideout isn't hard to get to if you know where to look. The tunnel over the tracks has completely collapsed in on itself-or so it seems. Getting home is like cheating at the worlds most dangerous game of jenga. When know exactly which two rocks to move, (they're marked with a black scribble that looks like an old tag) but if we make one wrong move the whole thing come tumbling down, trapping them in and us out. I watch JJ cautiously move the second rock to the side.
"Come on." She says unnecessarily  before excitedly scampering down the tunnel. I shake my head and follow her, awkwardly moving the rocks back in place before crawling through the narrow tunnel, carful not to nudge any other rocks.
It doesn't take long to reach the other side. But I suddenly wish it took longer.
The large tunnel is completely deserted, not a single shadow in sight (well there are actual shadows in sight). The backpacks of stollen food and clothes are all gone from their usual pile in the corner. All that's left are the long lasting flashlight set up around the room, I pick up the nearest one and scan the walls for a message they may have left. JJ immediately does the same on the other wall.
"K-Kay." She stutters. I hurry over to her and look at the wall where she's shinning her flashlight. There are two symbols on the wall in bright green spray paint. The first means goodbye. The second isn't finished-it means run.
Before I can process this I hear two loud bangs.
JJ falls to ground and blinding pain erupts in my left calf. I bite my lip as I fall to my knees and turn to JJ to check if she's ok when I'm hit in the temple and black out.