Batman watched the deal go down from the rooftops, the men below oblivious to his presence. The men on the left, he knew: two low-level arms dealers working for the Penguin. He'd already located their stash and their hideouts and left an anonymous tip for the GCPD. But the buyer was a new player altogether. There was something strange about him, something not quite right. The dealers seemed to sense it too. They were edgy.

Edgier than usual.

The moment the deal was done, they scurried back to the car. Batman had rarely seen a couple of career criminals clear out so fast. Not without seeing cops in the area. Or seeing him. The guy wasn't even intimidating. He was a thin, scrawny guy, wearing tattered jeans and a baggy sweatshirt. A woollen hat covered greasy dirty-blond hair. The Pisces logo marked every item of him clothing. It was a cheap brand of clothing, a thrift shop staple.

With his unkempt beard and dirty attire, the guy looked as if he'd been sleeping rough for months. But the way he carried himself… it was as if he owned the world.

As the black S.U.V. screeched away around the corner, the buyer turned around, black case in hand, and calmly left. His gait wasn't the shuffling hobble of a hobo, but the steady march of a soldier, poised and alert.

The Batman followed silently, shrouded in shadows. There were no lights in this area, just abandoned warehouses and empty lots. The buyer's footsteps echoed in the silence.

Suddenly, he stopped. Batman crouched lower as the buyer cocked his head, as if listening for something. He couldn't have heard anything, Batman thought. His cape stirred in the breeze as he waited, trying to figure out what had spooked the guy. Both men remained motionless, Batman on the roof, the buyer on the ground, waiting and listening. Almost a minute passed. Then the buyer turned to look at the roof, focused on the exact spot where his surveyor hid.

Then he ran.

Batman bit back a curse. He didn't understand how he'd been spotted; he hadn't made a noise, hadn't cast a shadow. He hadn't even been close. And now he was paying for that. His target was getting away.

The buyer was fast, his stride long and easy, like a practised sprinter. Hurdles, Batman surmised, would be no problem for this guy. The weight of the case of guns he'd purchased didn't seem to slow him down at all. He began taking turns at random, trying to lose his pursuer, forcing the Caped Crusader to leave his vantage point.

Batman leapt from the roof, dropping to the floor and rolling immediately into a sprint. Some hundred metres ahead, the buyer took a sharp left, breaking the line of sight. The vigilante was in danger of losing his man.

He took the turn just in time to see the runner hurtling towards the busy freeway. Glancing over his shoulder, he jumped the railing and stepped into the heavy traffic. Batman watched helplessly, still trying to catch up.

Horns blared and brakes screeched as drivers cursed the feckless pedestrian. The buyer moved without hesitation, as if the road were clear, and narrowly missed the tail-end of a vehicle in the first lane. The following car swerved away, almost colliding with the barriers at the edge of the road. In the second lane, the buyer wasn't so lucky.

The speeding sedan ploughed into his legs, throwing him up and over the roof. He tumbled through the air, head over heels, as the car sped on beneath his expression, Batman read no sign of shock or even pain.

Amazingly, impossibly, the runner retained his senses, seemingly unhurt, and pressed a hand momentarily against the top of the vehicle to steady his fall. He somersaulted away, landing on his feet in almost the exact same spot he'd been struck. The case of gun was still safely in his clutch. Without pausing, he lurched forward again, crossing the final lane.

Batman's eyes widened in disbelief.

On the other side of the road, the buyer turned around and the Batman was sure he had made out a self-satisfied smirk, before the madman repeated his daring feat on the other side, amidst the northbound traffic. This time, he got through untouched.

Now, he had Batman's full attention. The vigilante pushed himself up and over the railing and swept toward the road. For an instant it looked as if he would collide with the passenger door of a passing vehicle, but at the last minute he launched a line and swung across all six lanes.

As the vigilante landed, the buyer snarled and set off into a run again. Batman chased him in to a residential area of high apartments, dodging the various pieces of junk that were thrown back at him. The man was much stronger than he looked, throwing a bike with considerable force with just a flick of his wrist.

The runner took a narrow turn and by the time the vigilante had reached the alley, the buyer was halfway up the block of apartments, scaling the fire escape like a cat climbs a tree. Using a grapnel, Batman followed with ease.

The Dark Knight alighted on the rooftop, batarang in hand, and sank into a crouch. The runner stopped and turned, drawing his gun. For a fraction of a second, the Batman hesitated; the weapon was like nothing he'd ever seen before. It looked like something out of a science fiction movie, the metalwork in a flowing flowery design, glowing with a blue light that pulsed through three separate barrels. He couldn't be certain it was a gun, but he wasn't going to take that chance. A moment later, he'd released the batarang.

The guy howled in pain and clutched at his wrist as the gun flew from his hand. It clattered across the roof, closer to the Batman. The vigilante studied it with one eye, the other firmly on his prey. The black case of guns dropped with a thud.

"Talk."

The guy cocked his head but remained silent. There was something arrogant in his expression, as if he didn't realize he'd lost.

"It's over," Batman grated. He took a step closer. "Who are you. Who are you working for?"

The buyer looked towards his own weapon, the strange metal shining brightly in the moonlight. It no longer glowed blue.

"What's in the case?"

The runner only grinned.

Suddenly, his foot swept through the gun-case, lifting it into the air. The container slammed against the Batman's crossed arms and fell to the ground with a heavy thud, the contents spilling across the room: normal submachine guns. The Bat regained his bearing in time to see the buyer launching himself forward, delivering a flurry of punches, each of which Batman deflected, but only just. Seeing an opening, the vigilante aimed a blow of his own, but his opponent leapt inhumanly high. Batman heard the landing, directly behind him, and felt the foot sweep through his legs. He found himself lying on the ground, with the triple-barrelled gun aimed at the symbol on his chest.

"I guess we'll take it from here."

Vigilante and buyer looked up as one, both caught off guard. Two men, each in sleek black suits and ray-bands, stood on the rooftop, aiming their own weapons at the runner. Both men were in their thirties, one African American, the other Hispanic.

Batman was almost impressed. Their approach had been flawless, stealthy and well-timed. Their reconnaissance, on the other hand, clearly lacked refinement. A fifth figure stepped onto the roof behind them, his own otherworldly weapon trained on their backs.

The new arrival, Batman noted, was also dressed head to toe in Pisces apparel. He wore a hooded sports jacket and a pair of broken spectacles, the cracked lenses giving his eyes a strange appearance. The buyer floundered, moving his crosshairs between the two agents and the floored vigilante.

For a time, the two Suits flustered too, unsure of where to point their weapons. They backed off, trying to keep both enemies in their field of vision. Eventually, the Hispanic settled with aiming at the newest arrival, while the one Batman deduced to be in charge aimed at the buyer.

"What did I tell you, H?" the lead Suit said, shaking his head. He was the one who had spoken originally. "I said, make sure he's acting alone. Didn't I say that? Didn't I say those very words?"

H looked wide-eyed, glancing frantically at the two Pisces-clad gunmen while the other acted as though he had forgotten them. H began gesturing with his head, nodding a subtly coughing to get the other man's attention back to where he thought it belonged.

"Don't be looking at them. They aint gonna save you. You made the mistake, you need to take responsibility."

"Um, J," H said from the corner of his mouth.

"Don't 'J' me," his partner said dismissively. He turned to the two gunmen. "I'm sorry, this won't take a second. Just hold on. They've gotta learn sometime, y'know."

The gunmen exchanged puzzled glances, but didn't move.

"You had one job, H, one job. Now, when I tell you to do something, you do it. Right?" H nodded uncertainly, but J continued. "You just lucky Batman's here to save yo sorry ass."

The whole time he had been speaking, the crime fighter had been edging one hand towards his utility belt, slowly under the watchful –if distracted – eyes of the buyer. By the time J had finished, he had successfully withdrawn the smoke pellets.

He threw them to the ground and the rooftop was shrouded. Guns fired, bright lights slicing through the grey cloud with electronic sounds, bullets embedded themselves in concrete, the shots echoing in the night.

Batman rolled and replicated the buyer's own trick before slamming the palm of his hand into fallen man's cheek, knocking him out cold. Flipping backwards, he avoided another two rays of fatal blue light and hurled himself towards the silhouette of the new arrival.

The gunman went down, firing a final shot into the air as he fell. His head cracked against the roof and his eyes lolled in his head as he lost consciousness. When the smoke cleared, the two Suits were hauling the buyer to his feet, having placed him in cuffs.

"Good work, Batman. As always," J said. "I'm Agent J. That's my partner, Agent H. Rookie. You know how it is."

Batman walked by him, and crouched beside one of the guns, intrigued by the blue energy flowing through it. Intuition told him he wouldn't be allowed to keep it.

"You're probably wondering what that is, right?" Agent J said smiling. "It's a little piece of tech called-"

"Fission Carbonizer," Batman said, standing.

"Okay," Agent J said quietly. "Guess you're not wondering what's going on here?"

"You're agents from the non-existent Division Six, Extraterrestrial Defence and Security; top secret, unknown even to high-ranking government officials. Including the President."

"So you know those guys are…?"

"Aliens."

Agent J stared at him dumbfounded for a time. Then, nodding to himself, he retrieved his second detainee, who was just then coming round. Agent J slapped the cuffs on his wrists and smiled. His prisoner sighed and his eyes flickered as two thin layers of film slid across his eyes like curtains, closing and opening again. J looked at the Batman, who remained as impassive as ever.

"Seriously nothing? He just blinked with another pair of eyelids."

"They're gills," Batman said moving away towards the ledge.

"I know they're gills but- hey, how do you know that?" J asked. "You know what, forget it. Doesn't even matter."

He looked down and pulled a device from his inside pocket. It was a silver cigar-sized device, made of metal with a red light at the top.

"I'm sorry about this, Bats, coz I really respect everything you do and all, but," J began, but when he looked up again, he found that the vigilante had gone. For a moment, J remained silent, looking annoyed. Then he sighed, shook his head and put the neuralizer away. "K would like that guy."

Back at the cave, Batman sat before his supercomputer, studying the analysis of the alien gun. The blue energy it used for ammunition was astounding, and the technological uses would be vast. WayneTech could do great things with this. Of course, 'Division Six' wouldn't allow that.

Not yet anyway.

"Eventful night, sir?" Alfred inquired, entering from the study.

Batman nodded. "I came across a Cephalapoid at the warehouses. He was carrying a Fission Carbonizer. I managed to get a sample."

"Fascinating," Alfred said, oblivious to the consequences of such data. "I presume you are uninjured?"

"I'm fine."

Batman continued with his work. Alfred nodded and turned to leave, his medical skills, for once, unnecessary.

"I met Agent K's successor tonight," Batman added.

"Indeed?" Alfred said, pausing. "Is he a worthy replacement?"

Batman was silent for a while, and Alfred began to wonder if he'd become too engrossed in his work to answer. At length, however, he replied.

"Nightwing would like him."