Dr. E stood in the doorway with his hands behind his back, totally calm, like Nico and Rex had just walked into a meeting instead of a secret laboratory full of stolen animals and nightmare machines.
The massive room hummed around them.
The cables traveled along the walls and floor. Red warning lights lit the ceiling. A giant shadow machine in the center of the chamber whirled, its huge barrel pushing dark energy into the air with a terrible drone. Cages were lined up at the sides of the room. Rabbits, pigs and birds and others huddled together in terror.
Nico cracked his knuckles.
"Guess we should fight this fucker!"
Dr. E adjusted his glasses.
"Charming as always."
Rex moved forward with his shoulders tense.
"We are shutting down your machine."
Dr. E faintly smiled.
"And you are always welcome to try."
He pressed a button on a controller in his hand.
The floor shook.
Metal panels moved across the ceiling and steel columns rose from below, emerging into new machine designs. Within seconds six combat units marched into the room in a wide circle around Nico and Rex.
They were nothing like Dr. E's regular robots.
These were great. Taller than Rex. Their armor was black and silver, thick enough to stop heavy impacts. Their heads were narrow and angular with glowing red eyes. One arm of each machine ended in a cannon, while the other could shift between a blade, a claw and a hammer-like crusher. Tubes on their backs pumped thick streams of synthetic shadow fluid into glowing cores in their chests.
Nico blinked.
"Six?"
Rex frowned.
"That's annoying."
Dr. E raised a finger.
"Shadow Combat Units. Mark Two."
The robots all locked onto them at once.
Then everything exploded.
The nearest unit fired first.
A black beam whipped across the room toward Nico. But just before it hit, he disappeared in a storm of red and the blast punched a hole through the metal floor, sparks pouring everywhere. Nico reappeared behind the machine and punched it in the spine.
CLANG.
His fist bounced back.
Nico shook his hand.
"Oh, you've gotta be kidding me."
The robot spun instantly and swung a blade of dark energy at his neck.
Nico ducked low and slid under it, but two more units were already rushing him from the side.
Rex charged the biggest one.
He swung both fists hard into its chest with enough force to crack the floor beneath his own feet. The machine stumbled back a step and fired its cannon arm straight down at Rex's stomach.
BOOM.
Rex flew back and crashed into a wall hard enough to dent it.
"Okay!" he barked, getting himself up. "These things suck!"
Three more units opened fire.
The chamber filled with beams, explosive shells and shadow-coated metal discs that curved through the air like saw blades.
Nico sprinted between the attacks, feet pounding the floor so fast he sounded like a machine gun. He ran up a wall, kicked off, twisted midair and drove both feet into the face of one robot. Its head snapped back, but it still stood.
Rex grabbed a fallen metal platform and swung it like a giant bat, smashing it into another unit. The platform crumpled. The robot barely moved.
Dr. E watched with total satisfaction as the chaos unfolded.
"Do you see now?" he called out over the explosions. "This is what real engineering looks like."
Nico jumped back as a hammer arm hit the floor where he was standing.
"Yeah!" he yelled back. "Ugly and annoying!"
One of the combat units stepped forward and transformed both arms into linked cannons.
Its chest core brightened.
Then it fired a spread of black energy pellets through the room.
Nico's eyes widened.
"Rex! Move!"
Rex jumped aside just before the blasts hit. The projectiles didn't explode on impact. Instead, they splashed across the floor and walls like liquid ink, then rose into twitching shadow creatures shaped like wolves.
Rex stared.
"...What?"
The shadow wolves lunged at him.
He roared and smashed the head off the first one with a backhand. The second one jumped onto his shoulder and bit down with jagged shadow teeth. Rex grabbed it by the throat and threw it into a column. It splattered like smoke.
Nico got surrounded by two robots and three shadow wolves at the same time.
"Okay, that's new!"
A wolf snapped at his leg. Nico kicked it through the chest, then spun and dodged a cannon shot from behind. One robot swung a crusher fist that looked like a car tire. Nico ducked under its arm and zipped up its back.
He saw the glowing core in its chest through a slit in the armor.
"There you are."
He curled into a tight spinning ball and slammed forward.
CRACK.
The slit widened. The core flickered.
The robot staggered.
Before Nico could hit it again another machine grabbed him out of midair with a steel claw and squeezed.
Metal groaned around him.
Nico gritted his teeth.
"Okay. That is also new."
The claw tightened harder.
Rex saw it and rushed through a hail of blasts to help. He lowered his shoulder and rammed the grabbing robot with so much force that both machines toppled sideways. Nico ripped free then rolled off.
"Thanks."
Rex spat to the side.
"Don't mention it."
Dr. E pressed another button.
The six units formed up instantly.
Three moved to the front.
Three followed them and knelt, locking their cannon arms up.
Their cores lit up as one.
Nico frowned.
"I don't like that."
One second later a giant wave of synthetic shadow energy blasted across the room like a black tidal wave.
Nico and Rex bolted in opposite directions.
The wave ripped through the chamber, smashing rails, shattering empty cages, and blowing a piece out of the other wall. Nico ran flat-out along the side wall, keeping ahead of the wave, while Rex grabbed a steel beam and launched himself over the crest of the wave at the moment it reached him.
The attack finished with a terrible explosion.
Smoke and shadow rolled through the room.
Nico coughed as he landed.
"Okay," he muttered. "No more messing around."
Rex cracked his neck.
"Good."