"We jumped down the last flight of stairs just as the guard came out of the office. He pointed his bayonet at us and yelled at us to stop. Oh crap, I thought. I looked at Ben. He looked at me. We looked at the guard.
“Dude,” Ben said to the guard, pointing down, “your boot is untied.”
The guard looked down long enough for me to give him a swift kick between the legs. He let out a grunt and double over. Ben pulled his hat down on his face and toppled him over."
Nothing too elaborate for middle grade fiction. We'll see what the agent says!