When Mac woke up the next morning, Kenzie was curled up next to him. Sometime during the few hours he'd actually slept she must've snuck in beside him. Picking her up as she slept, he carried her through to the living room. Sitting on the couch, he tried calling Stella's cell phone again, but it went straight to voicemail. He threw her phone down onto the table and wrapped his arms around his daughter, breathing in the smell of her shampoo and Stella's laundry detergent, and fought to stop himself from crying.

Kenzie didn't want to go to daycare. In fact, all she wanted to do was see Stella and Mac was quickly running out of excuses for why Stella wasn't there.

"No!" she pouted furiously.

"Kenzie. You have to go to daycare," he said patiently.

"No!" she retorted. "Want mommy!"

"I know Kenzie. You'll see her later."

"No!" she cried. Tears bubbled in her eyes, her arms crossed as she glowered at him. Mac decided to try another tack. He retrieved Kenzie's sneakers from under the coffee table where they'd been abandoned the night before and knelt down to slide them onto her feet. However, as soon as he tried, Kenzie kicked her feet away from him, crying out, "No, don't!"

"Mackenzie Bonasera!" Mac snapped before he could help himself. Then he bit his lip, pinching the bridge of his nose to stop the tears which threatened to overwhelm him. No. He was not going to be one of those parents, who shouted at their children simply for being children. After all, kids were miniature humans. It was only natural for them to feel the same emotions as adults did, no matter how frustrating it became. No, he refused to take his fear and his frustration out on his daughter.

In the end, he decided to take her to the lab with him. His main priority was Stella after all. Until he found her, any other cases could wait. Besides, Kenzie had clearly struggled to sleep the night before as much as he had. In all probability she would fall asleep on the couch in his office. And he really didn't feel like fighting his way through all the traffic and diversions caused by the subway collapse.

"Hey, how's she doing?" Jo asked quietly as she entered his office.

"She wants her mom," Mac replied.

"Poor thing. No word from Stella?"

He shook his head.

"She's not at home. She left work at her usual time. Her car's not at the NYU lot. She's just disappeared."

"She'll turn up," she said, squeezing his hand gently. "Hawkes and I are heading down to the subway collapse to help. I'll see you later."

"Let me know if you find Danny."

XOXOXOX

Stella leaned back in the subway seat. She was starving. At least she still had some water left from work. But she couldn't help the nagging worry that no matter how carefully she sipped it, it would be gone far too soon. However, that wasn't the biggest worry. Sooner or later, the air down here was going to run out.

Don't think that, she told herself. Do not think that. You are going to get out of here. You'll see Kenzie and Mac again. Danny was right. Mac'll find you, just like he found Kenzie.

Her thoughts kept coming back to Claire. She'd been friends with Mac's wife. Claire's death had hit her hard, not as hard as Mac of course, but their shared grief had cemented their already strong friendship. That was when she'd started looking after him, since he'd stopped looking after himself. She wondered if Claire had experienced anything like this, sitting surrounded by rubble, waiting and knowing that there was a very real chance she wasn't going to get out of there alive. They'd never found her body, so they had no idea how or when she'd died. Her thoughts returned to Mac. How on earth would he cope with loosing someone almost the very same way he'd lost Claire? A lump formed in her throat. She tried to force it, and the thought that she was going to die there, away.

There was one thing she was grateful for: at least she had taken the plunge and told Mac that he was Kenzie's father. That way, if she didn't make it out of that subway tunnel, Kenzie and Mac would have each other. Stella blinked, realising that she'd started crying. She brushed the tears away quickly. Out of habit she pulled out her phone to check for signal. Nothing. If only there was a bar of signal, just enough to send a text to tell Mac where she was, that she was okay and so was Danny. And most of all, that she loved him.

Suddenly Danny was elbowing her in the side, bringing her out of her reverie.

"What is it?" she asked.

"Listen," he instructed. Her eyebrows creasing in concentration, listening carefully. Most of the passengers were silent, only a few were talking in quiet murmurs. Occasionally they'd heard other subway trains rattling past in nearby tunnels, but that was it. So far underground, they were ensconced away from the city above. Only now there was a new sound, and unlike the soft murmurs or the rattling of the trains nearby, this one was not comforting. The ominous creak, coupled with the ever increasing trickle of pebbles on the carriage roof, was far from comforting. Stella met Danny's eyes in alarm.

"Danny," she muttered. "You don't think.."

"I do," he nodded. "I think there's a very good chance this tunnel's going to cave in again."

XOXOXOX

Mac had long ago given up trying to work. He was simply sitting watching his daughter. When Kenzie had woken up, she'd started drawing. She loved drawing. Mac couldn't help but pick out the similarities between Kenzie and Stella. Her curls, her cheekbones, her smile – not that she was smiling much today.

His phone buzzed in his pocket. Wrestling it from his pocket he stared at the screen: Voicemail. Pressing listen he lifted the phone to his ear.

"Hey Mac, it's me. Listen, my car's broken down. I called the garage and they've taken it away so I'm gonna take the subway. Can you pick up Kenzie and I'll meet you at the lab? See you soon."

When the message ended, Mac realised he'd been holding his breath. He had to remind himself to breath. Quickly he checked when Stella had left the message. The day before, fifteen minutes after she finished work. But the notification hadn't appeared until now. Suddenly the TV caught his attention. Stepping out of his office so Kenzie couldn't hear, he called Jo.

"Jo. I know where Stella is. She's in that subway car with Danny."