Inside the armory, people gather spears and prepare to defend themselves from the approaching hoard. There is only the one door in or out, so you are effectively trapped, but trapped with a lot of weapons and a door that's narrow enough that you suspect it will limit their numbers to something manageable. Hopefully, if you kill or hurt just a few, they'll turn and run.
One of the men hands you a spear, then steps back cautiously, still unsure of whether or not to trust you. You turn your back to him and face the door with the others. You can hear the hissing of the lizards as they approach.
The first one leaps through the door with astonishing speed, catching you off guard, but another man steps forward and weaves his spear through the air, slicing and gutting the lizard all in a single fluid motion. You see how that man is holding the spear and adjust your stance. Two more leap in and you stab at one, hurting it, but not killing it. Another man finishes it off. With the next wave, you successfully fight down a lizard, and start to feel exhilarated. But that feeling quickly gives way to terror when you see what's behind the initial wave of lizards. It's the Big One.
You are amazed that it can even fit down the tunnel, but the massive beast wedges its way through. The other men are terrified. One of them is so distracted that a smaller lizard tackles him. You stab it with a spear and it rolls away, but the man remains down, clutching his injuries. The big one clears the tunnels and emerges into the room. You can see the young girl working her way around the side of the room, trying to flank it.