AN: This is the fifteenth installment of my personal challenge to write a tag for every episode. This is a tag to 1x15, Magnifying Glass. It's an AU where it really was the original Zodiac Killer the whole time, and not a copycat. I hope you enjoy, and please leave a review!

WARNING: This is so far one of the darkest things I've ever written. It gets very violent, and it gets graphic in the descriptions of violence. All in all it's just a bit disturbing, so be warned.

It was him. It was really him. The real Zodiac. Handwriting analysis had come back with a positive result. The same person had definitely written all of those letters. It wasn't a copycat. It was really him, and he was corresponding with some other killer out there, teaching them how to kill.

No one could believe this was actually happening. After all these years, the Zodiac Killer was back. He'd gotten away with at least five murders - although he claimed it was 37, now 39 - for fifty years, and now he was back.

"This is insane. It's really him? We're on the trail of the real Zodiac Killer?" Jack asked, although everyone already knew the answer.

"Yes, Jack. It seems we are," Matty replied, taking a deep breath and walking back up the stairs.

Mac just stared at his partner, the two of them sharing wide eyes and a slight smile. As terrible as this all was, it was also super cool. The actual Zodiac Killer was almost within their grasp.

"Dude," Jack said. "If we catch this guy, we're gonna be famous." Jack chuckled and let his smile grow wider, while Mac's fell.

"But we can't tell anyone."

Jack's smile slowly fell as realization dawned on him. He sighed, giving a resigned nod.

"Bozer's probably freaking out," Mac added, his smile coming back. His roommate did have a love of theatrics and a deep interest into the psychology of a serial killer. This probably had him bouncing off the walls in excitement, and maybe just a little bit of fear.

Mac would've been lying if he said he wasn't a little excited too. The possibility of finally catching the actual Zodiac Killer was insane, and something Mac had never guessed he would ever do. He could feel the buzz surrounding everyone as the news that they were hunting the real deal traveled around. Some people looked scared, others excited, and some just in shock. Mac could sympathize with all of them. This was quite the case, after all. He knew this was going to be very interesting.

But what Mac didn't know, was that there was an old man standing behind a tree on the other side of the street, watching through the open window. The old man had been watching for quite sometime, his discarded cigarettes in a pile on the ground beside him. He could see the blond boy directing the other agents thanks to the brightly lit house, and was confident that he couldn't be seen. The old man was shrouded in shadow, not even his glasses giving any reflections of light. A sadistic smile spread across his wrinkly face. If he was being honest, he'd gotten bored of killing back in 1974. One could only kill so much before even that lost its appeal. But he'd been watching the blond boy for a while now, and knew that causing the boy's death would be a treat. The couple in the park had been child's play, just something to ease himself back into it. Teaching others to kill all these years had been a nice pastime, but killing the boy would be fun. Watching the light slowly fade out of his bright blue eyes, death coming all too quickly, as he shot him again, and again, and again, and again...

The blond boy wouldn't escape like the other had, so many decades ago. He was so glad he'd gotten back into the game.

After several hours of processing evidence, Mac and Jack were finally able to head back to their hotel for the night. Despite knowing that they were in fact dealing with the real Zodiac, they still didn't have a real name, and no idea who he was corresponding with, teaching to kill. They checked in with both Riley and Matty - who each had their own private hotel rooms - before heading to the room they shared with Bozer. Riley had been able to decode only a few of the emails so far, and they were all about how to shoot or stab people in just the right places if you wanted them to die, or just to suffer. All in all, it was very disturbing stuff. Matty had spent some time with Vanessa's mother, informing her of their progress on the case.

Bozer started gushing about the case the moment Mac and Jack walked through the door. Mac just ignored him - he already knew all the facts Bozer was saying - while Jack just asked how he knew all these things about a serial killer.

"The anatomy of a psychopath is very intriguing, Jack. You know, given your line of work, I'm surprised you don't know more about 'em," Bozer responded, crossing his arms.

"We're spies, not detectives. We don't need to know all this creepy stuff you know, right Mac?" Jack said turning to the cracked open door of the bathroom, where behind Mac was changing into a pair of flannel pants and one of Jack's old army shirts. It was well after midnight, and they were all tired after such a long day.

"Well, what Bozer's saying does pay off to know sometimes, and I already know all that 'creepy stuff'," he said, pushing the bathroom door open to show his finger quotes. "But, on a completely unrelated note, I'm gonna head out to the vending machine outside to grab some food. You guys want anything?" Mac asked, grabbing a few dollar bills and his key to their room, just in case. He still couldn't believe that the three of them were all sharing a single room while Riley and Matty each got their own.

"Peanut m&ms, as always," Bozer replied with a smile, while Jack shook his head.

"Alright, I'll be back in a few minutes," Mac said, leaving the room and gently closing the door behind him. He knew most people in the hotel were probably asleep at that point, and didn't want to cause any needless noise.

The hotel was average in terms of how nice it was, but it was set up like a large motel, with areas open to the outside air after long hallways. The vending machine was in one of these outside areas. Mac silently made his way down the hallway and to the machine, considering what he might get. For once, he was actually kind of hungry, and they didn't have any snacks in the hotel room. Mac reached the vending machine, and turned his full attention to its contents.

How fitting that the hotel the blond boy was staying at was in Presidio Heights, at the corner of Washington and Cherry. Many years before the hotel had been constructed, he had murdered his cabbie at that very intersection. Strange how things come full circle. Even stranger was that as the he slowly came around the corner of the hallway his next victim's room was in, he saw the blond boy. The boy should've been asleep in his room, but instead, he was twenty feet away, staring at the vending machine. Oh well. This didn't change anything. The boy would still die.

But before the old man could take his first shot at the boy, a door swung open down the hallway and a middle aged man came lumbering out, his eyes quickly growing wide at the sight of the Zodiac himself with a gun drawn. Then several things happened at once.

"Mac, get down!" the middle aged man shouted at the blond boy, who immediately ducked, not even looking to see what he was ducking from.

Just as the words had left the man's mouth, the old man changed his aim to the one who had come through the door, and fired, putting a bullet in his shoulder and dropping him instantly with a shout.

"Jack!" the blond boy - Mac, apparently - called out to the fallen man. Before the boy could do anything, the Zodiac stepped forward and shot him in the leg, just enough to stop him from getting up and running. The boy let out a shout of pain and finally took his eyes off the other man who was now crouching - the Zodiac put another bullet in the same shoulder for that; he could die too then, just as slowly - and turned towards his attacker. He put a bullet in the boy's stomach, and relished in his cry of pain, relished in the dark crimson blood staining the boy's gray shirt. Another shot to the boy's gut, another scream, and more blood, so much blood, blood covering the boy's leg, his stomach, the ground, everywhere.

The old man heard a weak cry of "Mac" coming from the other man, so he put a bullet in the man's outstretched arm. After the boy was dead he would put a single bullet in the man's skull to end this, but he needed to have his fun first.

He turned back to the blond boy and shot him again, this time on the other side of his abdomen. He cried out even louder, and the old man could even see a few tears begin to fall because of the pain. He smiled. Why had he ever stopped doing this? He shot the boy one more time, and nearly shuddered in pleasure at the boy's scream. There was so much blood, so much delicious crimson blood flowing from the boy. One more shot and it-

Bozer stood in shock at the scene in front of him. Jack was lying closest to him, blood pouring from his shoulder and arm. Mac was lying down by the vending machine, bleeding out. The man in the black hood and glasses, the Zodiac Killer himself, lay beyond Mac, motionless. Bozer dropped the gun and fell to Jack, who was still conscious.

"I'm fine," he got out. "Get to Mac, and call 911."

"O-okay," Bozer stuttered in reply. He shakily ran over to Mac, but didn't pull out his phone. Since the gunfire had stopped, people were coming out of their rooms and screaming at the sight that greeted them. Bozer heard someone shout that they were calling an ambulance. He took a glance over at the killer, who was completely still. Bozer had just killed someone. For the first time in his life, he had fired a gun, and he had killed someone with it. And not just any someone, the freaking Zodiac Killer. But Bozer couldn't dwell on his swirling emotions right now.

He could tell that Mac was still alive, but he knew his roommate wouldn't be for much longer if he couldn't stop the bleeding. The next several minutes passed like seconds and hours at the same time. The police and two ambulances soon arrived on site, but Bozer didn't move. He had taken his shirt off and was holding it against the two bullet wounds in Mac's stomach that were closest together. There was just so much blood, and nothing Bozer did seemed to stop the flow of any of it.

At some point, Riley and Matty had come out and tried to help both Mac and Jack, leaving all of them covered in blood, the blood of their team, of their family. Bozer didn't really recognize any of it. The EMTs pried them all off, and began asking questions, but Bozer couldn't pay attention to anything but his friends as they were loaded onto separate ambulances.

"You have to put them together," he whispered, staring after them. "They'll freak out if they wake up and they're not together."

"I'm sorry?" the police officer asking him questions said, but Bozer didn't repeat himself. "I know this is hard, but I need you to tell me what happened," the young man gently said. He was probably around Mac's age, maybe a year older, and had green eyes that exuded sympathy and kindness.

Bozer took a deep breath, and tried to compose himself. He would be no good to his friends if he couldn't even help the police.

"I was getting ready for bed, and I heard gunshots, and shouting. I didn't know what to do at first, but after a second or two I grabbed my friend's gun from the safe, turned off the safety, and stepped outside. That guy was standing over my friend, pointing a gun at him, so I fired. I shot the gun and I shot that man straight in his hooded head." Bozer finished, and looked down at his hands, stained in Mac's blood. The deputy put a hand on his shoulder, and gently squeezed.

"You did the right thing," the deputy said, ducking his head to catch Bozer's gaze. "You're free to go to the hospital to be with your friends. They're gonna need you." The deputy handed Bozer his card and instructed him to call him if there was anything else he needed to say, and informed him that he would likely be needed at the police station to be interviewed again in the near future.

While Bozer was being interviewed, Matty had quickly changed and gotten them a cab. Soon, Bozer found himself in the cab, next to the window with Riley to his right, and Matty next to her. No one said anything about it being cramped, and the cabbie had enough sense to not ask about all the blood, simply taking his money once he had had dropped them off at the hospital.

All they could do was wait. Neither Bozer nor Riley were wearing shoes, or even socks, so a kind nurse offered them each a pair of slippers, which they gladly took. After several minutes of sitting in silence, Riley left towards the bathrooms. A few minutes later, she returned, her hands now clean of blood, and her face stained with tears. The sight of the woman Bozer loved in such a state had him almost breaking down, so he too excused himself to wash his own hands.

Bozer took in a shuddering breath as he stared at himself in the mirror. He was staring at a killer. He had killed someone. Yes, it was the Zodiac Killer, which did actually make him feel a little bit better, but still. It was a big pill to swallow. Seeing all the blood, Mac's blood, on his hands, was even worse. Bozer scrubbed his hands until they hurt, and all the blood was gone. He still couldn't believe this had happened. All Mac did was go to the vending machine, and he ended up nearly bleeding out.

When Bozer got back to the waiting room, it was to see Riley hunched over, Matty rubbing her back as comfortingly as she could. Bozer sat down next to her, and the girl immediately turned and wrapped him in her embrace. Riley was taking slow, deliberate breaths to try to calm herself down, but Bozer couldn't blame her. Thinking about it, Bozer let a tear fall himself. It was bad, and they all knew it. There was a good chance that Mac wouldn't pull through this time.

They sat there, all holding onto each other in some form, for the next few hours until a doctor finally approached them. They were the only ones in the waiting room. He gave them a gentle smile, and waited for them to compose themselves before he started speaking.

"Jack is going to be just fine," he started, letting them all give a small sigh of relief. They knew Jack would be okay - it was only a shoulder and arm injury - but it was still nice to hear it. "We were able to repair all the damage, and within a few months, he should make a full recovery. Angus, on the other hand-"

"Mac," all three said at once.

"He likes to be called Mac," Bozer added in a whisper.

"Mac, then, isn't out of surgery yet. I'm not going to lie to you. The damage is severe. His leg will be fine, but he's lost a lot of blood, and there's a lot of internal bleeding that needs to be stopped. Several major organs were hit, and need to be fixed. But," he paused, his voice more optimistic, "as long as his body doesn't fight it, he should survive. He's required a lot of transfusions and his body needs to accept the help we're trying to give it. If it does, he'll be okay, and he will recover. But if his body fights it, then his chances are slim. I would be praying, and calling any family."

"We're all he has," Riley said with a tearful smile. She then closed her eyes as more tears fell. Bozer turned around and did the same. His best friend could die.

"I can take you to be with Jack. If Mac, pulls through surgery, he'll be put in the same room, as per your request."

Matty, Riley, and Bozer followed the doctor down the halls until they reached Jack's room. He was still asleep, with a nasal cannula giving him extra oxygen.

"It's best if he rests, but he would wake up within the hour," the doctor said, gently shutting the door and leaving.

Riley took the seat closest to the bed and took the hand on Jack's good arm - his left arm - and gave it a squeeze.

"You need to wake up soon, okay?" she said to the sleeping Jack. "Because when Mac gets here he's gonna need you a lot, and you need to be awake for that."

Matty and Bozer were silent, taking a seat on the couch across from the foot of Jack's bed. Jack was in the bed closest to the window. There was an empty open space by the door where Mac's bed would be rolled when he came in. Bozer wouldn't allow himself to think in ifs.

Jack could hear a faint beeping, and a light pressure on his hand and at his side. Struggling, he slowly opened his eyes and saw a mop of messy curls right next to him. His shoulder and arm suddenly flared with pain, and everything came back to him. Going out to tell Mac he did actually want food, the Zodiac, getting shot, Mac getting shot, Mac screaming, Mac.

"Mac," he tried to say, but it came out as a whisper. "Mac," he said again, a little louder. This roused Riley, who had been asleep with her head on Jack's bed.

"Jack! You're awake," she said, her face breaking out into a huge smile. "How are you feeling?"

"Mac," Jack repeated, ignoring her question.

"He's still in surgery."

Jack turned towards the foot of his bed, where he saw Matty and Bozer standing up from the couch.

"He's been in surgery for a while now," Matty continued, her voice low, eyes downcast.

"He's gonna be okay," Jack said, his voice suddenly thick with emotion. "He has to be okay." He closed his eyes against the oncoming tears, but quickly opened them again at the opening of the door. It was the doctor.

The man began asking Jack some routine questions, all of which he answered, but his mind was still only concerned with his partner. Images of the man standing over his kid, shooting him time and time again, chuckling as Mac screamed, Jack being unable to do anything to stop it...

"We're going to put you on a pain killer and a sedative. You need your rest," the doctor said.

"I need Mac," was all Jack could say before he felt the pull of sleep taking him under again.

When Mac came to, the first thing he knew was pain, but the first thing he thought was Jack. Had the Zodiac killed him? The last thing he remembered was that black hood staring at him as he was shot again and again. He needed to know if Jack was okay. Mac tried as hard as he could to open his eyes, but to no avail.

"I think he's waking up," he heard. Riley? "Come on Mac, you can do it," the voice continued. It was definitely Riley.

He tried to ask about Jack, but the words wouldn't come out. Mac tried opening his eyes again, but it was too hard. Maybe he could just stay asleep a little longer.

"Come on," he heard from a male voice. Wait... "Come on, kid, you can do this, please."

It was Jack. That was enough for Mac to push even harder to open his eyes. After several more attempts, he finally succeeded, and was greeted by a dimly lit white room.

"Mac," came Jack's voice again, thick with emotion. Mac slowly turned his head to the left, towards the sound of his partner's voice.

"Ja-Jack," he managed. He couldn't say anything else before a doctor came in, saying things that Mac wasn't paying attention to. All Mac could do was stare at Jack, caught up in the fact that he was alive, the Zodiac hadn't killed him. Mac fell asleep again as the pain all over his body lessened, the last thing he saw being Jack's gentle smile.

Jack couldn't believe it. The doctor said that Mac was going to be okay. It had taken a long time, and it had been touch and go for a while, but since Mac had woken up as early as he did, he now expected the kid to make a full recovery. Jack could've cried in relief, but it looked like Bozer actually was. From what Riley and Matty told him, it was only because of Bozer that he and Mac were alive. Bozer had been the one to kill the Zodiac Killer himself. They weren't quite sure what they could and couldn't tell the police yet, but that would be decided soon. It was going to be quite the media circus. It wasn't every day that one of the most infamous serial killers of all time was finally found and killed.

Bozer himself was still a little rattled at the fact that he had killed someone, but Jack knew he would soon move past it, and start bragging about having been the one to kill the Zodiac Killer. It was such a very Bozer thing to do.

Jack knew that he and Mac both would likely be having nightmares for the next week at least, but they would be there for each other, just like always. The most important thing was that they were both still alive, and that was something Jack would thank God for every day.