Title: DO NOT CROSS
By: Ldinka
Pairing: DannyDon & implied DannyMac
Rated: NC-17
Disclaimer: I own nothing.
Warning: AU, slash, angst, death of the main character, language.
Beta: Thank you for your patience, Donna.

***

"Where's Mac?" asked Stella with irritation. She had been called at the scene at 6 a.m. because the dispatch couldn't reach him. It was almost noon and Mac still wasn't around.

"I don't know," said Sheldon thoughtfully. "It's not like him. Have you called him?"

"Yes! I've left more than fifty messages!"

"What's the problem?" Don demanded from the door way.

"Mac has disappeared." Stella threw up her hands in frustration.

"What do you mean disappeared?" asked Flack in surprise.

"Hasn't come to work, doesn't answer the phone. Just disappeared." Stella was really upset.

But Don thought about other person. The one who was going slowly down the corridor towards the lab. Since that day, when Mac had officially declared his and Payton relationship, Danny had become somewhat quiet and withdrawn. Don watched his friend submerging deeper and deeper in the abyss of dejection.

Only Flack and Aiden knew about Messer's hopeless and irremediable love to Taylor. Or rather – only Flack did. And just the other day, he'd found a very drunk Danny in some filthy bar and brought him home. And a wasted Danny was painful experience. Because a drunken Danny always did something he would be sorry for later. And Flack didn't want Danny to be sorry for that night.

Stella was discussing something with Sheldon, but Flack didn't pay any attention. He looked at Danny. Shadows under the eyes, hunched shoulders, sullen wrinkle on his forehead, dull hair, dull eyes. However, something new appeared in those eyes. Some determination, some distinctness. Flack felt cold growing in his stomach. It seemed that something bad, even terrible was waiting for them in the future.

Danny entered the lab and looked directly at Don. And the iciness in Danny's stare melted for a few seconds, revealing a small, soft smile. 'Maybe he isn't sorry?' Don hoped. The next second, Stella attracted Danny's attention:

"Stella, dear, why are you so nervous? It'll harm your health," he grinned. Bonasera, noticing Danny, just rolled her eyes and dropped down on the chair.

"Mac's disappeared," Sheldon explained to Danny.

"What do you mean – disappeared?" snorted Danny. Stella again repeated her story. Danny's answer was: "Have you asked Payton? They're…sort of together now". Don looked at Danny very carefully. Messer was surprisingly calm. That was incredible. Don remembered the condition of Danny's apartment and fists after Mac's breaking of the news. And now he was standing there and behaving as nothing had happened, as if he didn't care.

"I don't want to call her," Stella said. Everyone stared at Sheldon. The latter sighed sorrowfully and pulled out the phone. After a few minutes, Hawkes told them that Payton hadn't seen Mac since Friday.

"Well, I think we should start worrying then," frowned Stella. Everybody got silent for a moment.

"Let's go to his apartment?" half-asked, half-stated Sheldon. Danny just shrugged his shoulders. Don volunteered. "I'm going with you," Stella immediately responded.

After precisely thirty two minutes, Flack's car pulled up to the Taylor's building. Bonasera and Don went up to his floor and stopped by the front door.

"Looks like everything is quiet," muttered Flack. Stella knocked on the door. Nothing happened. She knocked harder. The door opened with faint grinding sound. "I don't like this," she whispered while Flack pulled out his weapon.

Slowly, they entered the apartment. Don called out Mac, but nobody answered. With big, full of fear eyes, Stella looked at Don and went into the bedroom. The door leading to the bathroom was slightly ajar. With trembling hands, Stella opened the door and turned on the lights. He was there. Lying on the floor. Covered with bruises and abrasions. With his face twisted in terror, a piece of bright against his cyanotic skin yellow DO NOT CROSS tape was around his neck. Flack barely caught the now unconscious Bonasera.

For the first time in his life, Don didn't know what to do. He was at a loss. With Stella on his hands and the dead Mac Taylor on the bathroom tile floor, he stood there and tried to think.

"First, take out Stella. Second, call Ma…who? Danny? Shit, Danny…" Now he had to tell the rest of the team about Mac's death. That was the end. Nothing would be the same. Especially Danny. Taking Stella in his arms, Don left the flat and came up to the neighbor's door and knocked with his foot. No one answered. He repeated the procedure a few times, until some old lady opened the door.

"I'm detective Don Flack, please, I need help." The lady reluctantly let them in. He put Stella on the sofa and called 911. In five minutes, all New York police knew that the supervisor of the day shift of the Crime Lab had been killed in his own apartment. The stuff of the Lab was shocked, shaken, scared. In ten minutes, IAB came into the picture. In twenty minutes, a temporary supervisor was appointed. In thirty minutes, Sheldon and three CSIs from night shift entered the crime scene. Stella and Don could only watch. There would be no other crime scene in New York until the bastard who had done it was caught.

"It's incredible! It's…disgraceful! That's terrible!" Stella could be heard near the elevators. Don came into the lab.

"What's going on," he asked.

"Nothing. That's the problem," came a quiet answer from the left. Flack looked at Danny. He sat in the corner with arm crossed on his chest. His cheeks were covered with stubble, red tired eyes hid behind the glasses. Having received no intelligible explanation from 'retired into his inner world' Messer, Flack turned his attention to Hawkes.

Pale and haggard, Sheldon answered. "We found nothing."

"What?"

"Nothing. The man spent the whole weekend in Mac's apartment cleaning it up. No fingerprints, no hair, no epithelium. The place is simply sterile. Not a trace. Even under the sink."

Then Maka started speaking: "He has spent much time at Mac's place. But after killing Mac, he took care of leaving no tracks."

"Okay, let's go and ask neighbors who came to Mac very often." Maka got up and went out. Stella and Don followed.

It was almost a midnight when Flack finally got to his home. And a big surprise in the form of Danny Messer was waiting for him under his door. "Have you been waiting for long?" By waving his hand and wrinkling up his nose Danny made it clear to Don that it wasn't really important.

Having let Danny in, Flack locked the door, put off the shoes and went to the living room. Danny followed him and flopped down into the sofa. Don went to the kitchen and came back with two bottles of beer. Putting them right before Danny's nose, Flack loosened the tie and threw off the jacket. Without a word, Danny put his arms around Don and buried his face in his neck. Flack stroked Danny's back and tried to decide what to do with his life. Everything was more or less understandable. Danny worshiped and adored Mac. All Don could do was to love Danny from afar. Danny was happy. Then everything was ruined. Tanglewood, the shooting. Mac pushing Messer farther and farther away. Aiden took care of Danny, but then she died. Don wandered why he decided to live after the explosion. But he survived and came back to work. Came back to be a precise and reserved Danny. One wonderful and sunny day, he saw Peyton and Taylor coming out of some fancy restaurant. And Flack understood that soon the situation would become even worse. He never told Danny about them. On hearing from Sheldon about Mac's declaration, Don wasn't surprised to find chaos instead of Messer's apartment. And a drunken Danny with blade in shaking hands. He didn't leave his friend out of his sight for a whole week, until Danny banished him.

And that night before Mac's death, Don took Danny to his place. And they made love. Well, Don called it love; Danny would call it sex if being asked. Next morning, Don went away, leaving a bottle of water and some aspirin for the sleeping Danny. And that little smile promised some hope to Don, but Mac again ruined everything. He died. Flack was very angry with that Taylor.

"We didn't learn anything much from the neighbors," Don spoke quietly. "They saw Peyton. They saw a guy who had visited Mac often. But no one saw his face. He always wore a cap or a hood. He's our major suspect and all we know about him is that he is a white man of average height with slim body." Don felt Danny tense in his arms. Flack froze. Because he felt soft warm lips caressing his skin.

"Thank you, Don," whispered Danny. "Thank you for everything. For being near, for being a friend in spite of my name, in spite of my stupidity and temper. You take me as I am. And I'm grateful for that. And I'm ready to thank you for the rest of my life". The blood rushed from Flack's face. That was the moment, the moment when a decision has to be made. The moment that would divide his life into "before" and "after".

"I love you, Danny. I always did. And I'll wait with patience for you to feel the same".

Bright piercing crystal-clear eyes looked into Don's. "Is that true?" Flack nodded. "Then I swear the day will come when I'll say those exact words with honest heart," said Danny.

That night was the sweetest and wildest in Don Flack Jr.'s life.

They lived in the lab; they looked everywhere, but didn't find the killer. The case was never closed. From time to time, some of them would spend an hour or so rereading Mac's file, searching for something new to come out. But they knew they would never solve the case.

The funeral was solemn and sumptuous. Peyton dressed in black, wiping her tears with lacy handkerchief. Danny stood among the team mates with empty eyes, with a worried Don by his side. Colleagues and friends, relatives and just acquaintances mourned for a great loss. Everything had changed. They would not be the same again.

A week passed. Danny spent more time with Don. The day shift had a new supervisor. They came back to normal gradually. Don waited. He was ready to wait.

Danny stood by the big tombstone. Cold biting wind swayed the flaps of Messer's coat. "I haven't brought the flowers" – his hoarse being carried away with fallen leaves. He smirked:

"We both perfectly know why." Taking a deep breath, Danny continued. "I've overcome…I've found the strength to go on living…You can hate me, it doesn't hurt any more. Now I'm with Don. Of course, I don't love him as I loved you, but I shall be happy in spite of anything. They'll never know. No one. Never. Aiden knew but she's somewhere there with you. Don thinks that there was nothing between us. Thanks to you by the way. You thought I was careless. You thought I was unassembled. But I've done everything clean and carefully. They'll never solve it, they'll never catch me". Nodding in satisfaction, Danny turned and left, never to come back.

Flashback

"Why Mac? Why? Couldn't you show some respect and tell me to my face? Why must I be the last to know about you and Peyton? Me? We were together more than a year!"

"Stop shouting, Messer! I'm sorry it turned out to be like this but I just…didn't have an opportunity…"

"You're such a coward, Taylor…"

"Don't you dare to talk to me like that"

"Oh, really. Not to dare? What do you think you are? What am I, a whore? Don't you know I have feelings, pride and self-appraisal?"

"I know you've got ones! You don't even try to hide them!" Danny draws back his arm to slap Mac but Taylor catches his fist and wrenches it.

"Danny, calm down. Don't make me hurt you"

"You're already hurting me, don't you get that?" Mac flings Danny away.

"Shut up and get out of my face," he snaps.

"Please, just tell me why?" Danny can't hold back the tears. He's groveling but he doesn't care any more. All he wants is to know why.

"Why?" Mac watches Danny with surprise. "Why? Don't you know why? Because you're you! I can't do it anymore. You keep on disappointing me more and more with each day. I don't want you to ruin my life. I want to be happy. I'm tired of running and cleaning up your mess. Sick of saving you from your own stupidity. I'm fed up with fear of disclosure. I'm sorry, Danny, but nothing will come of our being together. Are you satisfied? You're dismissed!"

Mac points at the door and turns his back to Messer. He doesn't see the emptiness filling Danny's eyes, his skin paling, his fists clenching. He sees nothing more in his life except hatred in Danny's face and red shroud before his eyes. And Danny can't stop. He continues kicking and beating Mac with the remains of the chair. His instincts tell Danny that cuts on his hands will cause troublesome questions.

Mac's not breathing anymore. Mac is dead.

Danny sits there, staring at the wall till dark falls. Mac's paranoia turned out to be good. He wanted secretiveness. No one knows about their relationships. None of Mac's neighbors know what Danny looks like. All he has to do is to cover the tracks.

Danny's a good CSI. In the night, he leaves the apartment to come back two hours later with his kit and a bag. He works through the whole Saturday, ignoring Taylor's answering machine. He really hates Payton's accented voice. Danny misses nothing. No fingerprints, no fluids. Having dragged Mac's body to the bathroom, Danny runs the finger over Taylor's lips. "You loved your job so much. I think you'd like it." He takes out the scrap of the tape and ties it round Taylor's neck. On Saturday night, after changing his clothes, Danny goes out the door of Mac's apartment, leaving nothing behind. His colleagues will never even guess that Mac was gay.

Burning the sheets and his clothes at some desolate building site on the other end of the city,

Danny looks at the flames, but sees only the sign DO NOT CROSS.

The end

***