The year is 20XX, on a small backwater moonbase, there are two guards on the same shift protecting a municipal backup generator, and spend most of their time being bored out of their minds.

They are both supposed to be on shift, and then da aliens attack!

Da aliens are dingbats and there's like four of them, wearing no significant armor, their stupid plasma bolts are slow as shit, and they have a limited understanding of sightlines, cover, or any other infantry tactics. Each could easily be killed by a single burst from the standard issue GX-35 assault carbines the guards carry, and would just sort of stand there while one was fired at them. Even just one lone human soldier stands a decent chance at repelling this attack.

When da aliens attack, Guard 1 is still on his lunch break even though he is supposed to have 30 minutes for lunch and it's been 55 minutes.

When da aliens attack, Guard 2 is standing watch at the front door with his fully loaded GX-35 assault carbine, but throws it down and flees as soon as he sees da aliens.

Da aliens get in and asemoclicate the backup generator's power supply.

"All of them? I thought the sly devil had 'em everywhere."

"All locked," said the High Priest. "All of them."

"Almost all of them," said a voice behind him.

Ridcully's tones did not change as he turned around, except that a slight extra syrup was added.

[...]

"Ah, Lord Vetinari," he said, "I am so glad to see you are unhurt."

"I will see you gentlemen in the Oblong Office," said the Patrician. Behind him, a panel in the wall slid back noiselessly.

"I, um, I believe that there are a number of guards upstairs trying to free--" the Chief Priest began.

The Patrician waved a thin hand at him. "I wouldn't dream of stopping them," he said. "It gives them something to do and makes them feel important. Otherwise they just have to stand around all day looking fierce and controlling their bladders. Come this way."