Steve followed his partner over the threshold into the small living room. The Carlyles, looking very much the older version of the couple they had seen in the photo in Kovalev's file, were sitting side by side on the green tufted sofa. They were holding hands, staring at the police officers milling about their house from under lowered knit brows.

Crabb glanced at them then faced Mike again. "They haven't said a word since they told us they don't have a son and they have no idea what we're talking about."

The San Francisco detective studied them for a long beat but didn't make a move to approach them. He looked at the sheriff. "I'll talk to them later." He moved through the living room into the kitchen; it was small but clean and neat as a pin. Even the dishes were done. His partner and the sheriff waiting by the door, he stood in the centre of the room and looked carefully at everything.

Then, without a word, he left the kitchen, brushing past Steve and Crabb, stepping briefly back into the living room to head down the hall. There were four open doors, two on the left and two on the right: a bathroom, laundry room and two bedrooms. One of the bedrooms had been turned into a sewing room, with a brand new Singer and an ironing board.

Mike looked in all four rooms; the closets in the bedroom were open. He turned to Crabb. "That door at the back of the kitchen beside the fridge. Does that lead to a basement?"

"A basement of sorts," the sheriff nodded with a half-shrug. "It's more of an underground shed. We've been through it twice, there's nobody down there - "

"I want to see it," Mike said flatly, striding out the door and back down the hallway into the kitchen. Braddock, who was standing in front of the Carlyles in the living room, watched the lieutenant almost charge by. His eyes snapped to Crabb, who glanced at him with raised eyebrows as he followed the homicide detective back into the kitchen.

The lieutenant opened the white wooden door on the far side of the fridge. There was a dark opening, lit only by a weak amber bulb on the ceiling with a long string attached to the pull-chain. There wasn't a staircase, just an old steep wooden ladder nailed to the beam holding up the kitchen floor.

Mike stared down into the dark recess and exhaled loudly in frustration. He knew he couldn't, and shouldn't, attempt the ladder with only one good arm. He took a step back and looked at his partner; Steve crossed immediately to his side and looked down into the basement.

Realizing Mike's dilemma, Steve patted him briefly on the shoulder as he moved past him and turned to start down the ladder. "Are you okay to do it?" Mike asked, frowning in concern.

As he stepped onto the first rung, Steve looked up and smiled reassuringly. "I'll take my time, don't worry." He did, eventually disappearing into the darkened basement. Crabb and Martinez quickly followed.

Crabb took his flashlight out the second his feet hit the dirt floor; Steve, who was brushing the dirt from the ladder off his hands, nodded in appreciation when Martinez offered him his own flashlight. Snapping it on, Steve moved the beam around the large, cluttered, dirt-walled room. There were wooden shelves against two of the walls, loaded with everything one would expect to see in a house in the country. Many of the shelves were stocked with non-perishable groceries and other household items like toilet paper and laundry detergent.

There was a large freezer in one corner. Steve picked his way over the uneven floor and opened it; it was filled with frozen food. He reached in and moved a few items then closed the lid and took a step back.

He ran his flashlight against the back wall. There was a large stack of wooden doors, windows, sheets of plywood and pallets leaning against the wall. He looked at Crabb. "Did you check behind there?"

The sheriff nodded. "There's a small cold storage behind it. Yeah, we checked it out. It's empty. They said they used to use it but they don't need it anymore."

Nodding, Steve played the flashlight beam over the remainder of the damp and musty basement, satisfied there was nothing down there. He glanced towards the ladder; he almost regretted having to tell his partner that the odds were now pretty good that Lonsdale wasn't here.

With a grateful nod, he handed the flashlight back to Martinez and crossed to the ladder. It was more painful climbing up than it had been going down, and he was gritting his teeth by the time he made it up to the kitchen.

Mike had retreated to the middle of the room and he was looking around, frowning. He knew when Steve hadn't said anything that the basement was a dead end, but he was determined not to give up the search just yet. He had a feeling there was something he was missing, and he was damned if he was going to leave the house before he was satisfied they had done everything they could.

He watched as the younger man stepped up onto the kitchen floor, grimacing. He frowned and took a step closer. "Are you okay?" he asked quietly and Steve nodded, patting his partner's arm reassuringly once more.

Crabb and Martinez climbed up the ladder and joined them in the kitchen. Mike had returned to the centre of the room and was looking around again, a slight frown on his strong features. Steve watched him closely, knowing there was something his partner was trying to work out.

Mike took a step towards the counter and stood there for a silent beat, looking at two single light switches with separate plates on the wall under the cupboard. He reached out and flicked the right one up; an overhead light came on near the back door. He turned it off and reached for the second one and flipped it up as well. Nothing happened. Frowning, he flipped it on and off several times. Still nothing.

He turned slowly to Martinez. Very quietly he said, "Officer, could you ask Mrs. Carlyle to come in here, please?"

"Yes, sir," Martinez said with a curt nod and strode briskly from the room.

There was a sharp knock on the back door and all three cops jumped slightly, looking at the door. They could see Murtagh in the small window, gesturing wildly. Crabb crossed to the door and opened it.

"Did you just turn something on and off?" Murtagh asked excitedly.

Crabb frowned, glancing over his shoulder at Mike, who was still standing near the counter. "The lieutenant flicked a light switch a couple of times. Why?"

Murtagh grinned and waved at them. "Check this out," he urged, stepping backwards away from the door and moving quickly to his left. Crabb, with another glance at Mike, who was suddenly right behind him, followed Murtagh into the backyard. Steve was trailing slightly behind his partner.

Murtagh was pointing at a small exhaust fan protruding from the wall about a foot above the ground. It wasn't running. "That," the state trooper said eagerly, "was going on and off just now, like someone was flipping a switch."

Mike, who was staring at the exhaust fan, looked up at the young officer and smiled slightly. "I was…" With a quick, almost triumphant look at his partner, who smiled with a soft snort, Mike strode back into the kitchen. Braddock and the Carlyles were standing with Martinez in the centre of the room.

His face an unreadable mask, Mike crossed to the counter. He pointed at the light switch as he faced the older woman. "What's that for?"

Her eyes, which had been fixed on his, her face expressionless, turned slowly to where he was pointing. "It's the switch for the light above the back door," she said simply with a slight, annoyed shrug.

Mike stared at her for a long beat then looked towards the back door and the switch plate right beside it. "Steve," he said softly. The younger man stepped closer to the back door, opening it so they could see the fixture, then he flicked the switch. The light went on. Looking back at the group standing in the centre of the kitchen, he turned it off.

Staring at Mrs. Carlyle, Mike reached out and flipped the switch under the counter. Nothing happened. In the ensuing uncomfortable silence, Steve closed the back door.

"What is it really hooked up to, Mrs. … Carlyle?" Mike asked coldly, emphasizing the name.

"I told you, it's for the back door. It hasn't worked in years." It was a feeble attempt at an explanation and she was trying her best to sell it, everyone knew.

Mike looked past her to the husband, who was looking down and chewing on the inside of his cheek. After several long, tense seconds, Mike looked at Braddock. "Take them back into the living room, please, Sergeant."

"Yes, sir." Braddock started to usher the Carlyles out of the kitchen.

Mike turned to Crabb. The sheriff raised his eyebrows with a sharp, impressed snort then turned to the ladder and started back down to the basement. "Get Alvin and Bill in here," he barked to Martinez as he disappeared down the ladder.

As Martinez opened the back door, Mike turned to his partner. "I'm going down," he said flatly, stepping towards the basement door.

"Wait, no," Steve said suddenly, reaching out to grab the older man's right arm and pull him to a stop, "no, you can't do it with one hand, it's too –"

"I can do it, Steve," Mike turned on him almost angrily, his eyes flashing. There was a tense beat then he sighed softly. "I have to…"

After a long silent moment, Steve nodded. "Okay, but I'm going down before you –"

"No, you aren't," Martinez said loudly from behind Mike, and they both looked at him, startled. "Sorry, but, ah, you aren't up to doing that either," the big CHP officer said with a smile, nodding at Steve. "I'll go down first and, sir," he looked at Mike, "you come down after me and I'll spot you, okay?"

Smiling gratefully, Mike nodded. As Martinez crossed to the ladder, Mike looked at his partner and winked.

It took longer than normal, with Mike having to quickly drop his right hand from one rung to the next while keeping his balance, but with Martinez on the step below him, he managed to work his way to the basement, only slightly out of breath. When Steve dropped the last two steps to the dirt floor, his eyes snapped to his partner, who nodded with a brief smile.

All eyes on him, Mike walked to the middle of the dark, crammed cavern, facing the back wall. He immediately noticed the stack of plywood and pallets. "What's behind there?"

Crabb took a step towards him. "A small cold storage they don't use anymore. We opened it – it's empty."

As the others watched, Mike's head tilted up slightly as he looked at the area where the dirt wall met the ceiling. He looked back at the stacked wood again. "I want to see," he said evenly, keeping his gaze on the wall.

Crabb, with an eyebrows-raised glance at his officers, nodded, and Martinez, Ayers and Murtagh crossed quickly to the back wall and began to move the pile again.

Steve, his eyes snapping back and forth between Mike and the officers working quickly, took a step closer to his partner, who was standing perfectly still, watching and waiting.

The door to the cold storage started to appear. When Murtagh moved the last large sheet of plywood, Mike crossed deliberately to the door and opened it. The damp musty smell was almost overwhelming. It was pitch black. Without turning, Mike held out his right hand and Martinez, who was hovering slightly behind the lieutenant, snapped on his flashlight and put it in the detective's hand.

Mike ran the light slowly over the walls of the small, empty room. He was halfway down the right side wall when he stopped, hesitated, then glanced at Martinez. The CHP officer took a step closer, leaned forward and stared where the beam was pointing.

Straightening up slowly, Martinez took a half-step back and turned to look at the sheriff. "There's a door," he mouthed.