Kayla Donora is riding through a very urban and crowded area of New York City. Turning a corner sharply, she almost runs into another biker. But, no worries. She keeps going to a more residential part of the city towards her apartment.

Mac is on his way out of his apartment, getting ready for another typical day at the office. He stops at the door, remembering something. Smiling slightly he turns back to retrieve whatever it is.

Kayla continues to weave through various obstacles. Finally she reaches her apartment building and heads upstairs. She reaches her hallway and looks down the hall. It's empty.

Mac is heading out again, now with a brown package under his arm.

Kayla thinks about it, then gets on her bike again…why not?

Mac opens his apartment door and steps out.

Kayla zooms past him on her bike. Surprised, he drops his package and turns around. A short distance away, Kayla has stopped to laugh. Mac turns toward her, silently shaking his head and smiling.

"Morning," she say's casually, as if discussing the weather.

"You're back," Mac notes.

"You always notice," she replies smiling now.

"You always almost kill me," he states shrugging.

"You have a job for that," Kayla laughs and notices the package Mac dropped. "Watch you got there?" she asks, looking at the box.

"Oh, just um, stuff for work," Mac mumbles unconvincingly.

"Oh, right…your friend. Well, I better get going to school."

Not moving, he looks up at Kayla. He's got to ask. "Who told you?"

Unlocking the door across the hall, she shoots across her shoulder, "You just think you're good at lying." She closes the door leaving a poor, confused Mac staring after her. He smiles once more and heads out.

At the lab, Stella walks through the hallway looking through the windows of various labs looking for someone. She goes to the entrance and spots Mac signing a form at the front desk. He puts his pen down as Stella comes up behind him. Without a word, she reaches for his cell phone that is hooked on his belt and pulls it off. She flips it open and turns it on for him. He looks up at her realizing that she had been trying to call. Stella pushes the cell phone to him and grabs his sleeve, pulling him away.

At the crime scene, Mac, Stella, and Flack look at the body.

"We got a call, about nine this morning, victim found in the trash bin behind a grocery store." Det. Flack goes over the case with Mac and Stella. "Coroner said she died an hour earlier-around eight. Victim is Kathleen Donora, 21. Lives downtown."

Flack and Stella look at Mac who is staring intently at the body. Seeing that he isn't going to respond, Flack continues. "Parents deceased, no other family but sixteen year old Kayla, her sister. She was her legal guardian, so social services are picking her up at school." Flack pauses again, glancing uncertainly at Mac before continuing. "I don't know, she was barely getting by with some min-wage job, she had no life but that devoted to her sister…easy way out? Or maybe Kayla got tired of having a big sister look after her."

"Kayla has an alibi" Mac says quickly looking up now. He turns to Stella. "Process the scene. Danny and Aiden will help when they get here. I'm going to talk to Kayla." Stella nods, a concerned look on her face.

Mac gets in his car and sighs deeply. He closes his eyes. Some day he's having.

At Kayla Donora's high school, she is being talked to by officers. She looks to be in considerable distress, and curious onlookers gather around. Mac makes his way toward the officers and spots Kayla. She jumps up when she sees him and begins to sob uncontrollably in his arms. Mac does his best to comfort her, but has to ask his questions. They sit down and begin to talk.

Back at the crime scene, Aiden takes pictures while Danny looks around for evidence. He kneels down at a broken beer bottle by the dumpster. He looks closely at the end and sees blood. After taking a sample, he notices a blood trail and follows it.

Aiden takes pictures of the bottle that Danny found.

Danny is still following the trail for who knows how long. He is in an ally way between two tall buildings (imagine that in New York). Engrossed with the blood, he hardly acknowledges his surroundings.

Aiden is now following the blood trail, taking yet more pictures as she goes.

Danny is surprised when the blood trail suddenly stops at some boxes. He finally stops to look around and what he sees isn't good. All around him is markings and signs relating to the "tangle wood boys." He now knows for sure the case is gang related and no suicide. Something moves behind Danny. Jumping he shines his flashlight toward the noise and upholsters his gun.

Aiden continues after the blood trail but stops dead when she hears a gunshot. She looks up and whispers, "Danny?" She secures the camera around the shoulder and takes off. "Danny!" she now shouts. She skids to a halt in the entrance to the ally and makes out a figure at the end. She takes out her weapon and runs toward it. It's Danny and he's not moving.