Check, one, two...

He tracked down Cmdr. Smegg, and with great enthusiasm yelled
"Reporting for duty, SIR!"
Smegg stepped back, surprised by Zodar's voice, which was maybe a
little louder than it had to be.
Smegg regained himself and calmly delivered a response...
"Um, right, I think I'll need you to go take one last final look at
the new missile launcher. I have a feeling we might need to use it on
this mission..."
"Yes sir." Zodar replied and headed off towards the missile launcher
as instructed.
The missile launcher was enormous, but Chris had it under control.
There were only a few points that needed inspecting, it was actually
several different systems, combined together to form one machine.
Simple, really.
Chris held his clipboard and pen ready as he checked each system
carefully.
Turret Calibration Ok?
Check.
Projectile Arming System Ok?
Check.
Launcher Barrel Clear?
Check.
Interface Relations Ok?
Check.
Safety Systems Functioning?
...
Zodar found a console and ran a test program.
The program will simulate an error and the launcher's safety systems
should abort any operation.
...
"What? The systems are... failing? I have to report this to Cmdr.
Smegg immediately!"
Zodar contacted Smegg over radio.
"Sir, you won't believe this, but...um..."
"What is it Chris?"
"Um... the safety systems on the launcher are malfunctioning."
"What?! Zodar! Get out of there!"
"No, it's ok. It's a simulation..."
"Whew. Well, uh, find the problem. It shouldn't be a hassle for you."
"I'm right on it, but there's another problem, sir."
"What?"
"This launcher was checked before, and it passed."
"Are you saying that an engineer lied on his report?!"
"No. I'm saying that we may have a saboteur on board. There were no
guards here when I arrived. It could have been almost anyone... I'll
keep you posted. Zodar out."
Chris couldn't stop thinking about the situation while he was trying
to find the problem.
"Now why would someone mess around with the safety systems?"
He checked the wiring inside a panel.
"I mean, we all trust each other here."
Chris checked the safety sensors.
"Well, almost everyone trusts everyone."
He tightened a few bolts.
"I know I trust everyone, but that just my nature."
He checked underneath the launcher's base.
Zodar stopped abruptly.
"Hey, isn't there meant to be six cogwheels?"
Zodar looked at the mechanism. It was like a jigsaw puzzle, only
round and there was a piece missing. But then again, every jigsaw
puzzle Zodar owned had at least a piece missing. They just lose
themselves half the time.
There was one cog missing and it's axle had been cut right through.
A clean cut. Probably a laser.
"My guess is, we find the cogwheel, we find out saboteur."
"Who would do such a thing?" Zodar thought, while carefully attaching
a replacement cog to the what was left of the axle.