Beckett looked out at the glowing beacon of lights that was Times Square at night. It wasn't hard, from this vantage point, to see where the 'Dark Angel' legend might have emerged: it was difficult to see the scaffolding of the LED screens...difficult, but not impossible. Could anyone have picked them out of a lineup? Not a chance in hell. But could they have been seen? Quite possibly.

Castle came over and handed a red solo cup to his girlfriend. "It's sprite."

"I know," Beckett replied, smiling as she took a sip of the sweet beverage.

Castle looked out at the lights of New York City from their rooftop vantage point, wincing as the techno music behind them got kicked up another level in volume. "When did I get so old?" he whined.

"When you started paying Alexis' college tuition," smirked Beckett. She leaned in to get closer to Castle's ear so he could hear her over the blaring music. "But hey, think of it this way: if you're going to live to 450, you're not even a teenager yet."

"Great," Castle replied, rolling his eyes. "But will you still love me when I'm all pimply-faced and geeky?"

"You know I will," replied Beckett with a genuine, affectionate smile.

Castle returned the smile as Dave Grenholm made his way over to them. A young couple was following him. "Hey guys," he pointed out the couple behind him to the two Guardians, I want you to meet Troy and Jessica Albertson. They manage the school when Alex or I can't be there."

Troy, another tall, thin tracer with dark hair and piercing blue eyes, shook Beckett's and Castle's hands while the petite, blond-haired Jessica simply waved. "Dave told me you're the ones investigating Alex's death?"

Beckett nodded. "Was there anyone at the school who might have wanted to see Alex harmed?"

Jessica shook her head. "No, Alex wasn't the type to start fights with anybody."

"He was far more likely to run away from a fight...at top speed," Troy chimed in. "Now, Dave, on the other hand..."

"Alex would always force Dave to do all his dirty work," Jessica agreed.

Dave shrugged off the complaint with a sad smile. "That's why we worked so well together. He was the brains, I was the brawn."

"Alex was a classic conflict avoider," said Jessica. "So if something came up that he didn't want to deal with, he would ask Dave or Troy to take care of it."

The music behind them cut off unexpectedly as a voice yelled out, "Hey, I think that's them!"

The whole of the party seemed to make a push toward Castle and Beckett's little corner of the roof. Three black-clothed men were running along the rooftops toward the group...but they were coming from uptown, not from the loft side of Soho as they'd talked about. Beckett reached for her phone, wanting to call the boys; then she cursed as she realized that neither Ryan nor Esposito would have a phone on them. Rule #1 of their runs had been simple: don't bring anything that can be linked back to you if you dropped it. That included their badges, service weapons...and their cell phones. For the first time Beckett wished she had been the one who could read minds, because she couldn't think of any other way to get a hold of the other two detectives...

As if in answer to her prayers, a familiar voice echoed through her mind. Beckett? Castle?

Beckett immediately projected through the mind-link. Ryan, where are you guys?

Just jumped the Flatiron, on our way to you, replied Ryan, why?

Beckett replied by pulling her service revolver from her back holster and clicking off the safety. We've got copycats coming in from uptown, Beckett replied, stay away from Times Square.

Roger that, Ryan and Esposito replied simultaneously through the mind-link.

Beckett started to repeat her conversation to Castle when he stopped her with a hand on her shoulder. I heard. He linked to everyone but Lanie. The hum of Castle's shield energy surrounded her. You think these guys are trouble?

Has to be, replied Beckett, you heard what Dave said earlier. Any tracer with enough experience to be tempted to try one of our runs also has enough sense to know how risky it is.

Be careful you guys, chimed in Ryan.

Two of the copycats were putting on an impressive show for the enthusiastic audience of partygoers...all except Dave, who was staring at Beckett's service revolver. He had seen cops have strange reactions to tracers before, but this..."Detective Beckett?" he asked, hesitantly, "You don't really think these guys are dangerous, do..."

The third tracer was the one that Beckett had all her focus trained on. The one that wasn't jumping any more than necessary. The one who hadn't even attempted a single trick. The one who was pulling a sighted pistol out of the back of his pants...

*BANG*

Beckett aimed and fired before the tracer was able to get a shot off. The tracer collapsed, clutching his left arm, then got up and staggered off. Beckett took one step toward the ledge but was stopped by Castle's hand on her arm. We need to call this in, Kate. Ryan, where are you guys?

49th and Broadway, just on the other side of Hershey World. Everyone ok? asked Ryan.

Beckett got the shooter in the arm. They're heading north on 6th avenue, replied Castle.

On it, replied Ryan and Esposito.

Beckett felt the mind-link disconnect as she turned to Castle. "We don't have anything on the guy right now, Kate," Castle said quietly. "You're the only one who saw the gun pointed over here. You know what that means."

When Beckett hung up the phone, Dave crossed the roof to face the two Guardians. Castle and Beckett were both surprised at the look on the face of the man in front of them. They were expecting shock, even anger on the younger man's face. Instead, Dave looked grateful. "Detective," he told Beckett, "I don't know how you got that guy, but thank you..."

Castle was stunned. "You *saw*..."

Dave shook his head and waved over a few of his friends, who seemed to be pushing each other to face Beckett and Castle. Finally four members of the group stepped forward...each of the two men and two women held up pairs of high-powered binoculars. One of the young men spoke for the group. "We all saw the guy. That gun was pointed right in my direction."

Beckett knew she shouldn't be pushing her luck. She had four witness who could corroborate the need to fire her weapon. And yet, it almost felt like a matter of personal pride...she knew she had to bring it up. "You know those guys weren't the Dark Angels, right?"

"We know," replied Dave, nodding. He called for a fifth friend to come forward. "Flip does the reels for everybody on the team. He even did Alex's reel...anyway, this lunatic was crazy enough to risk his video camera trying to get Dark Angels video. You got 'em, Flip?"

Flip nodded solemnly. "Yeah, I got 'em."

Dave volunteered to connect the camera to his television to confirm that Flip got what Beckett would need to confirm the identity of the potential shooter. Beckett paced nervously as the two tracers worked with the equipment. The television blinked to life, and Beckett and Castle joined the two men to see what they had.

Beckett watched the three men on the screen as they came closer and closer. When the trio were a building away from where the tracer had opened fire, Flip zoomed in on them. He clearly got each of the three men's faces on the screen...ending with the shooter as he pulled out his weapon.

Dave gasped as he recognized the face of the man on the screen instantly. "Mad Dog?"

It amazed Castle that someone with the nickname of 'Mad Dog' was not immediately on anybody's list of potential suspects. "Who's Mad Dog?"

"He applied for a teaching job about a month ago," replied Dave. "*Really* talented kid, but his references all said he had anger management issues, so we turned him down."

"Is that really a surprise, considering his nickname is 'mad dog'..." muttered Castle.

Beckett ignored her partner's comment. "Do you still have his application?"

Dave nodded. "We have all of his paperwork on file. I can get it for you from the office first thing tomorrow."

"Anyone know who the other two guys are?" asked Castle.

One of the witnesses approached the screen carefully. "Flip, can you back up until I can see the guy on the left?" Flip rewound the video until one of Mad Dog's accomplices was visible. "And the guy on the right?" After Flip complied, the girl who had been directing the cameraman declared, "I know those guys. They run that underground ninja school in Brooklyn."