Having already put a trace on both Mac's home phone and cell phone, Flack and Mac waited while the rest of the team went back to the lab.

Finally his cell phone rang and he put it on speaker. "Taylor."

"Mac," came the whimpered response. "I'm sorry."

Tears welled in his eyes and he struggled to keep control over his voice. "Stella, where are you?"

"It was me," she told him. "Peyton saw me."

Flack and Mac looked at each other thoroughly confused. "Stella, what are you talking about? What do you mean it was you?"

"She looked like…" The line went silent.

"Stella?!"

A new voice, sounding very much like Stella only stronger, came on the phone. "She's fine. She's waiting for you."

Before Mac could respond, he heard the dial tone.

Flack was on his cell when Mac hung up. "We got a trace," he told him. "Abandoned warehouse near South Street Terminal. Units are on the way."

"Tell them not to do anything until we get there!"

Flack expertly dodged through the Manhattan traffic while Mac sat quietly trying to decipher Stella's message.

"Don, what if Stella has a twin sister?"

"I think she'd know," he responded.

"Not necessarily. The only life she had known was the orphanage and the occasional foster family. What if, and I know this is a stretch, but what if she has a twin she never knew about?"

Taking a brief moment to lay on the horn at a taxi that had cut him off, Flack shrugged. "I guess it's possible. Would explain why Peyton and the witness swore it was Stella they saw."

"It could also explain the similarities in DNA at the scene."

The sound of sirens could be heard as Flack neared the warehouse. He had barely come to a complete stop when Mac jumped out of the car.

Mac's cell phone rang again. "I'm here."

"Nice show outside but I want you to come in alone. Do it or she dies." To emphasize her point, she did something to make Stella scream in the background. "No tricks."

He turned to Flack, his jaw clenched. "She wants me in there alone. No backup."

"I can't let you do that."

"Yes you can. I'm doing it either way. If anything goes wrong – get Stella out." He ran off before anyone could stop him.

Cautiously, he stepped inside the warehouse and closed the door. "I'm here," he announced.

Nothing.

"I'm alone. Now let Stella go and we can talk."

"I don't want to talk," replied the voice so eerily similar to Stella's.

Someone stepped out of the shadows and Mac could just make out the silhouette. There was no mistaking the mass of curls. "Stella," he whispered, walking towards her. "Are you okay?"

The figured reached over and pulled out another person – with the same curly hair. As the two figures stepped into the light, Mac stopped. He had been right. Stella had a twin.

"What do you want? Why frame Stella?"

"I want her to suffer like I suffered."

His eyes sought out Stella's. A gag in her mouth partially covered a bruise forming on her cheek and he winced upon seeing a bloodied gash on the side of her temple. But with her eyes, she managed to let him know she was alright for the time being.

"Who are you?"

Stella's twin grinned menacingly. "Isn't it obvious?"

"What's your name?"

"Does it matter?"

"It matters to me. I care a great deal about Stella and if she has a sister, I'd like to get to know you too."

"The name's Angie. I didn't even get the pretty name," she hissed, pulling at Stella's hair and making her close her eyes in pain. "She had everything. She was all Mom ever talked about. Stella was so perfect. She was so beautiful. I look just like her, why wasn't I beautiful?"

Mac knew he had to tread lightly. "You had your mother," he offered. "You had something Stella never had."

"Yeah, some mother. When she wasn't drunk and whining about missing Stella, she was out on the streets making enough money so she could drink and whine again." She ripped the gag off of Stella's but still held on to her. "You had everything and I had nothing. Nothing. You have a nice job, friends who care, the perfect man who you knew you could have in a heartbeat if you wanted." Still holding firmly to Stella, she raised the gun at Mac. "Say goodbye to your perfect man."

"Angie, please, don't," Stella pleaded. With what strength she had left, she struggled to push the aim of the gun away from Mac but Angie shoved her to the ground. Stella looked up just as a shot rang out. "MAC!" she cried.

Time seemed to freeze for them in that instant. Stella staring at Mac through tears, Mac staring at Stella wide-eyed and Angie holding the gun aimed at Mac. In another instant time caught up with them and Angie dropped to the ground - dead.

Mac glanced behind him and saw Flack standing there with his gun aimed on Angie. "Thank you for not always listening to me," he muttered then ran over to Stella and untied her hands. "Are you okay?"

Not trusting her voice, she shook her head and clung to him and he to her.

While Mac waited for Stella to get checked out by the EMT's, he gave Flack his statement. "Thank you again," he said.

Flack nodded. "When I saw you were right, I knew if you shot her you'd have to live with feeling like you killed Stella. Couldn't let you do that."

Mac had not even thought of that issue. "Don, but you…"

He smiled at him. "I'm fine. Trust me; it would have been far different for you. I'm just going to get Stella's statement then you can take her home. You're place is still a mess, though."

Mac waited a few minutes then walked over to the ambulance as Flack was finishing up with Stella. "Ready to get out of here?"

She merely stood up and walked towards Flack's car.

"If you need anything…" Flack offered.

"Thanks. Um, do you think you can pick up your car later?"

He handed Mac the keys. "No problem. Just let me know where."

"Thanks once again, Don." With a weary smile, Mac warned, "Just don't get too used to my thank you's."

tbc….