Major Crime Bullpen, later that afternoon

When Jim and Blair walked into the bullpen carrying the confiscated sound device between them, they were subjected to friendly hoots and comments from their coworkers.

"What have you got there, an alien zap gun?"

"Get that from your friend in the tinfoil hat, Sandburg? He's been back looking for you."

"Very funny," Blair said. "Now help us find a place to put this gadget." Somebody moved a chair, and they set it down carefully near Jim's desk. It had been wrapped in an industrial-size plastic bag by the evidence tech who came out to the apartment, but it was still clearly visible. People gathered around curiously and the chatter grew louder.

Simon appeared at his office door. "I'm trying to get some work done around here," he groused. "What's going on?"

"We found this aimed at Milo Spalding's apartment," Blair informed him. "It's some sort of sound projection machine, like nothing we've ever seen before."

Simon took a look. "Interesting. Well, come into my office and give me a report," he said.

When they were inside, Blair began to explain. "Someone was using it to harass Milo Spalding, both to make him sick and to make him think he was hearing voices. The device can send subsonic sounds, which apparently can make people sick. It made us sick. But, Simon, Jim could hear it! He could hear sounds below the range of normal human hearing!"

"With Blair's help," Jim clarified.

"And the machine can also project voices from a distance," Blair continued. "The voices probably bombarded the poor guy constantly, telling him to kill himself. He was depressed and ill anyway, so it must have eventually pushed him over the edge."

"It was easier to use on him since he lived alone, I'm sure. It's not quite the same if two people hear the same voice," Jim said.

"Yeah, but his wife said he was hearing voices when he lived with her," Blair remembered. "Either she's lying or she's in on it. Or both."

"I guess you're not going to give me that nice straightforward suicide verdict I asked for, are you? This is getting messy," Simon said. "But I'm still hoping we can get it solved before the papers get hold of it. Do you have any other information?"

"Yes," Jim said. "I could see the faint traces of something, probably an identifying mark, that had been removed from the machine. It was a letter Z, shaped like a lightning bolt. Does that ring any bells?"

"As a matter of fact," Simon said, "it does." He closed the office door. "Have you ever heard of Zigler Technologies?"

They shook their heads.

"It's a high tech weapons company, based here in Cascade. They're engaged in top-secret research on non-lethal, or 'soft kill' weapons, made to incapacitate, not kill. A lot of it is military research, but the police department is extremely interested in what they might come up with, and we've already bought things from them that are in production."

"Like those stun grenades, flash-bangs?" Blair asked. "Or rubber bullets?"

"Exactly," Simon said. "They're working on a lot of other non-lethal weapons that are still in development, covering a wide range of technologies. I know they're working with chemical, biological, electronic, and acoustic weapons, and who knows what else. The problem with them, of course, is that it's hard to get the right balance between using too much force and too little. Non-lethal can often easily become lethal by accident, or they may be designed to operate at a range from non-lethal to lethal."

"Lasers on stun?" Blair suggested.

"Yes," Simon replied, "and I've also heard that some of these weapons are designed to cause permanent injury, or to kill you indirectly. If you're a pilot and a soft-kill weapon blinds you, you're probably going to crash the plane. I don't know much about it because it's mostly top secret. There's a lot of testing before anything is approved."

"Acoustic weapons, like our machine out there," Blair realized.

"Right. I suspect it wasn't obtained legally, since I'm not aware that such a weapon has been approved for production," Simon said. He frowned. "Yet another reason to get this case figured out real soon. I'm not sure what the charge or charges would be in this case, though. Theft, probably. Harassment, probably. But it still looks like suicide, not murder."

"I feel like I've seen that Z logo somewhere before," Jim pondered. "My god, now I remember where I saw it. It was the letterhead on some papers that I saw at the widow's house today, in the possession of a friend of hers named Kurt Luker."

"The friend that's more than a friend, you can bet," Blair said. "Sure, he'll help her deal with her grief on a little post-funeral holiday in Paris." He snorted. "Come on, Jim, I'm going to call Zigler Technologies and see if they've heard of him. Let's get moving." He pushed his partner towards the door.

Jim allowed himself to be pushed. "The truth," he said to Simon as they exited, "is that he's in a hurry to solve this case so he has time do some new tests on my poor ears."

"Tests that will enhance our understanding of the capabilities of the department's most unusual detective," Blair retorted. "It's all for the good of the department."

"Glad to hear you're so altruistic, Sandburg. Just close the case soon. That's all I ask." He closed the door behind them.

When Blair called Zigler Technologies and asked if they recognized the name of Kurt Luker, he was immediately transferred to Peter Zigler, the president of the company.

"Oh yes, Detective Sandburg," he said, "I certainly do recognize the name. He was one of our top salesmen until three months ago. That was when we discovered that he had allowed one of our clients to see a product that was still in development. We have extremely strict rules about not revealing information on our technologies before they're ready for prime time. We will never reveal any information about most of our government contracts because it's classified. Luckily, the project he showed to the client wasn't a government contract, or he would have been in even deeper trouble. But I couldn't trust him after that. He said what he did was just part of being a good salesman, but in addition to breaking the rules I think he may have accepted money from the client. At any rate, I fired him immediately."

"Mr. Zigler," Blair pursued, "do you have an acoustic weapon in development that can project voices and subsonic sounds?"

There was a gasp at the other end of the line.

"We've just recovered such a weapon as part of a crime investigation."

"That sounds like a weapon we're currently developing but haven't released yet. It's still very secret. We have some prototypes that are being tested, but not all the bugs have been worked out. Are you telling me that Luker had one?"

"I don't know, Mr. Zigler, but we're going to find out."

Kurt Luker's house, early evening

It wasn't hard to find Kurt Luker's address, and they were soon at the front door of his rather imposing residence in one of the finer areas of Cascade.

"Nice house," Blair observed, ringing the doorbell, "but the Spud Palace would be nicer. All he has to do is marry the merry widow."

After a short delay, the man came to the door. He looked very surprised to see them.

"Good evening, Detectives," he said. "Why have you come to see me? As I told you before, I barely knew Mr. Spalding."

"Can we come in, Mr. Luker?" Jim asked politely. "We have some questions we'd like to ask you. Just routine."

"Actually, I was on my way out," he protested.

"This won't take long. I'm sure you'd be happy to help your good friend Mrs. Spalding by assisting the police in their investigations." Jim said. "Can we talk in the living room?" He and Blair practically herded Luker into the room. They all sat down.

"Mr. Luker," Jim began. "I understand that you were formerly employed by Zigler Technologies?"

Luker's face hardened into a mask. "What does that have to do with anything?"

"Just answer the question, please. Were you formerly employed by Zigler Technologies?"

"Yes."

"You were fired by them three months ago?"

"Yes," he admitted, tight-lipped. "We had a difference of opinion."

"Did you take any property belonging to the company with you when you left?"

There was a silence.

"Did you rent an apartment across the street from Milo Spalding?"

"May I show you something?" Luker asked, rising from his chair quickly and crossing in a few steps to a cabinet. He opened a drawer as Jim and Blair rose from their seats. Before they could react, he threw something towards them and ran from the room. There was a loud bang and the room filled with smoke.

"Oh, great," Blair groaned, trying to see his way through the smoke. The face of his partner emerged from the mist. "Are your ears okay, Jim?" he asked worriedly.

"I'm fine. I had just enough warning to dial everything down. Come on, let's go after him." Jim grabbed Blair's arm and led him through the slowly dissipating smoke. When they reached the central hall, Jim stopped and listened. "I hear him underneath us in the basement."

They tried the several closed doors in the hallway, quickly determining that it was the locked one. Jim tugged at it and finally drew his gun and shot off the handle. They cautiously looked down into the dim recesses beneath them, but their quarry was not in sight. The Sentinel could hear sounds of movement, but they were not nearby and a little muffled. He went carefully down the stairs, motioning Blair to follow.

Luker was at the far end of the large basement room, trying unsuccessfully to open a door that looked like it led to the outside. What looked like a porch light shone through the tiny pane. He turned around and saw them advancing on him.

"Halt!" Jim called. "You're under arrest!"

Luker pointed a large gun at them, and they dove for cover. Something hit the wall next to them and fell to the ground. When Blair picked it up, he found that it looked like a small beanbag.

"Beanbag bullet?" he guessed.

"Yep," Jim said. "Small but painful. He may have an arsenal of non-lethal weapons down here. Be careful."

More tiny beanbags came flying towards them, hitting the wall harmlessly.

"Put down your weapon, Luker," Jim called.

The man began to work at the door again, more desperately. "How did you figure it out?" he wailed. "I don't understand how you figured it out."

The detectives got up, keeping behind cover but trying to move towards their prey.

Luker saw them coming and let go of the door. Grabbing something off a worktable that looked like a flamethrower, he began to shoot foam towards them. The floor was soon covered with it, and they backed off. Jim put a finger in it and discovered it was extremely sticky, and wouldn't come off his finger.

"Hell, Jim, why don't we just go around? I don't think he can get back this way, now that he's covered the floor with foam," Blair said. They raced back up the stairs, out the door and around the side of the house to a small stairwell and boarded up door leading to the basement. "He's right behind here, I'm sure," Blair panted. They began to pry the boards off the door.

They could hear Luker moving around inside, but when they got the boards off and Jim kicked the door in, they didn't see him immediately. Blair poked his head around the corner, there was a blinding flash, and Blair drew back with a scream. "My eyes! I can't see!" he cried, stepping backward in confusion and almost falling.

Jim caught him and took a quick look at his eyes. They were closed tight and tears were beginning to spill down his cheeks. "I'll take it from here, Chief," he said, unceremoniously pushing him into the corner of the stairwell. "Stay here." Blair pressed himself back against the wall.

Jim aimed his gun towards the door. "Make it easy on yourself," he called. "Give it up." Staying outside in the stairwell, but focusing sight and hearing inside the basement, he heard something being sprayed, and saw something shiny cover the floor. Then he heard the man's slow movements in the other direction. Jim stepped cautiously inside.

Suddenly, Luker slipped on whatever he had put on the floor. He skated helplessly towards the piles of foam he had created as a barrier, fell into a large pile of it, and was immediately enveloped. His shout for help was muffled as he inhaled and the sticky foam caught in his throat. He began to choke.

Jim listened to the man suffocate and knew he was powerless to save him. The floor was too slick for him to cross and there was too much foam around him. Luker was frantically thrashing and trying to pull himself out of the immobilizing substance, but very quickly he stopped moving and breathing. When Jim heard the man's heart stop he shook his head and turned back to his partner.

Blair was still flattened against the wall with his eyes closed. When he heard footsteps coming towards him he tried to cringe away.

"It's me," Jim said. "We got the bad guy, but I'm afraid he's dead. How are you doing?" he asked him, tilting his head up and taking a better look at the squeezed-together eyes and the reddened skin around them.

"Okay, I guess."

"Can you open your eyes?"

Blair slowly opened his watering eyes. The pupils were highly dilated. "I can't see anything," he said in a panicky voice. "I can't see anything." He squinted and turned his head blindly from side to side.

Jim could hear his partner's heart beating fast with fear. He took out his cellphone to call for police and medical support.

"Do you think this is permanent?" Blair asked in a shaky voice, touching his eyes with a trembling hand.

Jim wanted to reassure him, but he really wasn't certain. He didn't want to set up false hopes if Luker's weapon had been set to blind permanently. "Give your eyes some time to recover. That was a pretty bright flash," he finally said.

"I stuck my head inside and he zapped me. Was that stupid, or what?"

"Not nearly as stupid as the late Mr. Luker, Chief."