The sun has set, but the brilliant glow of Conventia's millions of lights blot out the stars. I look up, hoping to catch a glimpse of a ship passing. They at least look something like stars. But Conventia is closed this week, and nothing shines in the sky. I sigh and slosh my mop around in its bucket before squeezing it out and slapping it onto the pink tiles of the walkway. As usual, I can see no dirt on them, but I have to mop them anyway, in case of germs.

A few strokes and I dip the mop again, into the microbe-killing solution that fizzles and foams like . . . like the soda-cream fountain in the winners' room at the Invader trials. That cascading soda looks so delicious, but I will never be allowed to taste it. They say I don't have the right mentality to destroy a planet. Instead, I'm a member of Mop Unit 7. No advanced military training, no title, never even a chance to hear someone call me Invader Per. Just a mop and a bucket and the rest of my near-endless life.

It gives one time to think, something I both love and hate. As far as the Empire is concerned, I'm just another green-eyed female, twenty marks in height — not short, but not quite tall enough to command respect. That doesn't matter much when I'm alone. My mind can wander the galaxy, reliving the stories of Skoodge and his conquest of Blorch, Tenn and the miswired SIRs, Zim the Defective, and the tales of the great Tallests of the past. I love imagining the comforts of the Couch or . . . what if I met Zim?

I knock on his door, disguised as a native creature. He answers, his defective SIR bouncing around the room behind him.

"What do you want, Earth female?"

"I'm not an Earth female," I say as I drop my disguise. He stands, stunned, for a moment.

"Bow before ZIIIM!" he commands. Not wanting to anger him, I do.

He orders me to clean up his base.

"But Zim," I say, "The Tallest sent me to help you conquer the planet." This is not true, but I don't care.

"Help Zim? Zim needs no help, foolish smeetling!" He glares up at me. I must be nearly twice his height. "Now go back to whatever dirtball planet you came from!"

"Per! Quit standing there like a busted robot!" I jump, my reverie shattered, and turn to face Fipe, my supervisor. He's a skinny creature, a bit shorter than me and purple-eyed.

"Sorry," I mutter submissively as I squeeze out the mop and start cleaning the floor again.

"If this happens again, I'm putting you up for an EET. You're acting too defective," Fipe says, coming over to check my work. His threat hardly fazes me anymore. I know how many EET requests I have registered against me, and the number hasn't gone up since he started saying he'd report me six months ago.

"Looks okay," he says, and his spider legs unfold and carry him off to check on someone else. I look around. Only four more large squares of tile to go. I can finish in a few minutes if I hurry. That means sloshing some extra cleaner on the floor, but it'll dry before Fipe comes back to check it.

Back in the Mop Unit headquarters, I find a quiet corner and sit down to think. I have to find some way to get rid of these thoughts, the images and scenes that constantly jump into my mind. I could try to get them programmed out, but that would probably result in me being declared defective, and besides, I like them. They just can't stay stuck in my mind forever or I'll go insane. When I was young and something wouldn't go away, I could tell another smeet or scratch it on the wall or something and it would quit. Now, though . . . If I mar the walls at all, I'll be sent to Planet Dirt, where they don't give workers any time off. If I tell anyone, they'll put in an EET request, and I can't afford any more. Wish I knew how Zim drove the Control Brains crazy at his EET. Maybe I could manage something similar. . .

"Per, come quick! There's another raid happening!" Walet says excitedly, grabbing me by the arm and practically dragging me down the hall toward the main room where the huge transmission screen is.

"So there have been raids for the past two years. Why is this one a big deal?" I ask, trying to free my arm from his claws.

He opens the door and the announcer's voice floods into the hall. "We bring you continuing coverage of the raid on the Irken military training planet of Devastis. To recap, the mysterious black ship whose appearance has preceded each raid uncloaked for several minutes in orbit of Devastis, during which time it fired a cannon sweep that knocked out the power to the entire planet. The surface is in mass confusion, with battery power the only source of energy to fuel the battle against the raiders. No one knows when they will come."

"I bet it's Zim," someone says from just inside the doorway. I step inside to see Fipe talking with Yall. Fipe continues, "I mean, no other race could come up with technology like that, whoever's in it has obviously been to Devastis before, and only a defective would even think of doing something like that."

"Besides," Yall says, "he'd try to destroy anyone who stole his calling card. A power outage is just a big 'Zim was here' sign, really."

"Exactly," says Fipe. I roll my eyes. A power outage is an effective method of confusing one's enemy and giving yourself a strong strategic advantage. No wonder these two are cleaning drones. Then again, I am too, but I, at least, refuse to accept it as my only purpose in life.