Will dug his fingers into Data's wrists, trying desperately to get him off. Data was so engrossed in his attempt to kill Captain Troi that he did not notice Beverly come up behind him. The doctor put a hypospray up to his neck and before he could turn around she had injected the substance. Beverly and a security officer caught him as his legs buckled under him, and they pulled his limp body off of Will Troi. Beverly laid Data on the floor. She then looked up at Will. "Are you all right?"

"Yes," he said. "Where-" Picard came walking briskly down the corridor, rubbing the side of his head where Data had hit him. He looked at Will.

"Deanna has left with a shuttle to God knows where," Picard said crisply, irritated. "The shuttle is out of tractor beam range, so we will have to catch up with her and then use the tractor beam to pull her back into the ship. We'll get her back, Will," Picard told Will, who nodded in the way that inferred that he understood but didn't like what he was understanding. Quite frankly, Picard was fed up with the whole situation himself. Normally, he absolutely loved solving mysteries but this mystery had brought Will worry and emotional pain over his wife, Data's friends confusion and concern, and him a sore head. Picard frowned down at Data, lying unconscious on the floor. "What in heaven's name is going on with the two of them?"

Beverly was busily scanning Data again. "I have no idea."

"Doctor I want you to run those tests again and see if you still can't find anything. I'll be on the Bridge," he called over his shoulder as he walked away.

Beverly sighed. She too was frustrated; she knew nothing new would turn up. Still, she followed the captain's orders. They moved Data to Sick Bay and Beverly and her medical staff ran all the tests they knew how to run.

"Whatever it is, I can't find it." Beverly swore to herself quietly. She was the chief medical officer, and she couldn't do anything. Not one thing. She felt so helpless that it made her feel inferior to her title and her duty. "Can't you just tell me what's wrong with you?" she asked Data, not expecting a response.

"Doctor?" Beverly turned to see Tasha standing at the edge of the room, looking very uncertain whether she was allowed in or not. Beverly smiled. "Come on in, Tasha."

Tasha walked over to Data's side. Beverly watched her slide her hand underneath his and hold it, entwining her fingers around his. It made her feel even more guilty that she couldn't figure this puzzle out.

"You don't know what's wrong, do you?"

"Nope." The doctor walked back to the results displayed on the computer screen, determined to look it over just one more time. Maybe she had missed something, though a little voice in the back of her head told her she hadn't. She angrily pushed it away and stared at the numbers and diagrams. "I wish I knew what it was though." She pursed her lips together. Had there been any other instance such as this? Change in personality? Unexpected behavior? Mutiny?

The word mutiny rang through her head. There had only been a single case of mutiny among the Enterprise crew. She didn't know how she could have forgotten it, but it had been so many years. But it could be the answer she was looking for.

"There is one possibility…" Beverly murmured to herself, walking slowly back over to Tasha, deep in thought.

"What?"

"It was a while ago…yearsago. Will, Miles O'Brien, Deanna, and Data transported down to a planet; we though there might be people stranded there, but we found no one. When they returned, Deanna, Data, and Miles committed mutiny against the captain. We later found that they had been possessed by three spirits who wanted our ship to transport the rest of their companions off the planet, and to find their own bodies again."

"So…you think Data is possessed by a spirit?" Tasha asked. Beverly nodded. "How do we get rid of it?"

Beverly grimaced. "That's the hard part. There's an extremely strong particle beam that when exposed to a person causes the pain receptors' activity in the brain to increase dramatically, and for some reason the spirit cannot hold onto its host's body. That's why Will wasn't effected. At the time of the possession, his arm was broken, so the spirits couldn't enter him."

"In other words, the beam will cause him tremendous physical pain?"

Beverly nodded with an apologetic smile. "That's why it's the hard part."

Tasha sighed and nodded. "If that's the only way, then let's do it."

Beverly suddenly grew excited, despite the circumstances. They were finally getting to the bottom of this. "I'll notify the captain."

"There," Jean-Luc said. He and Will were looking at a primitive planet, its native people were few. The shuttle had gotten there first and had already landed on the planet, and though they were unhappy about having to go down and retrieve Deanna, at least they had found her.

"Commander Shelby, assemble and away team and-"

"Crusher to Picard."

He held up a finger to a waiting Commander Shelby. "Picard here. Have you found anything?"

"Yes. Can you come to Sick Bay?"

Picard turned. "Commander Shelby, you have the Bridge. Will, would you accompany me?" Will nodded and followed him onto the turbolift.

Beverly welcomed them with a smile as he stepped into Sick Bay.

"Do you remember when Data, Deanna, and Chief O'Brien committed mutiny?"

He nodded sarcastically. "Yes. Vividly."

"I think we may be dealing with the same situation here. I can't find anything else to explain their strange behavior," said with confidence.

"Then you want to try the particle beam?"

"Yes."

Picard nodded again, grimly. "Very well, Doctor. Proceed." Beverly turned and walked back to the place where she had already set up the device that would omit the beam. Data lay, still sedated, underneath it. Tasha stepped back as the doctor turned on the machine, and the beam shot downward, covering Data. He automatically sucked in a sharp breath and began to groan, his muscles "spastically" tensing and relaxing, tensing and relaxing. Tasha put one hand over her mouth, anxiously wondering when the spirit would leave his body. A minute went by.

"Increase the voltage," Picard said. Beverly, her brow creased with utter distress that she had to do this to a friend, increased the voltage. Data's entire body stiffened, his groans becoming sharper with each passing moment.

"Increase," Picard said again, wanting as much as everyone else in the room to stop the beam completely. But he could not. It was the only way.

Beverly's reluctant hand reached up and turned the beam up to the highest voltage. Data's eyes were squeezed tightly, tears beginning to come from the corners of his eyes. His eyes suddenly shot open, and darted to Tasha.

"T-Tasha…" he whispered brokenly. "Tasha…!" he cried.

"Tasha…Tasha…" Data whispered. He lay on the floor, breathing hard. The pain was in his head too, as well as his body and soul.

He realized that moment that he had been manipulated. All this time, he had been someone else. "I…am…Data…" he whispered. "I…am…Data…"

Erik screamed, his trembling hands gripping his hair. He screamed louder and louder. But he struggled to his feet, gathering his strength. He leapt on top of Data, choking him with his hands.

"You are Erik!" he screamed. "You are Erik! Do you hear me?! You are Erik!!" With strength Data hadn't even known the man had, Erik threw him backwards, making him crash against the chair. Before he could get up and fight back, Erik shoved him back into the chair. "If you are not…" He never finished his sentence, but with an evil, insane smile stumbled toward Data. The pain was physically ringing throughout the darkness, yet still the man stumbled and struggled towards him. Data felt too weak to stop him.

The light above the chair revealed a noose in his hand. Data suddenly found himself bound hand and foot to the chair again. He struggled and tugged helplessly at the rope, but he could not move.

Erik wrapped the noose around Data's neck and tightened it steadily until the rough threads of the rope began rubbing the skin on his neck raw. Data's surroundings, the ringing that echoed through the place, the light above him, his pain, his grip on his consciousness, all seemed to slowly fade away from him, fleeing just out of his reach.

The ringing grew louder and more intense, making his enemy vault backwards in pain. The ropes fell from his hands and feet, and Data fell from the chair onto his knees, his hands flat on the floor. He coughed and sputtered in pain. Erik gathered his strength against the pain that was practically deafening them. He kicked Data in his ribs, knocking him to the floor. He then pushed him over onto his back with his foot, and placed his foot on his chest, and pushed on it. Data felt like he was suffocating. And when he looked into Erik's cold, heartless face, he felt like he was suffocating even more; with fear.

"Who are you?!?" Erik growled.

"It isn't real…it isn't real…" Data whispered.

Erik reached down and grabbed the end of the noose that was still hanging from Data's neck, and pulled until Data's whole upper body was off the floor. Data gasped for air. After a few moments, the man released it and Data crashed to the floor again.

"WHO ARE YOU?!?" Erik screamed.

"I am Erik…" Data whimpered in fear. "Don't hurt me…don't hurt me please…"

Picard watched Data's face grimly. It had been over a minute and a half now, and still nothing had happened. Nothing but Data screaming and groaning with pain, calling Tasha.

But suddenly the expression on his face changed. It went from pain and longing to pain and…revenge. Anger. Data's eyes opened again, but this time they were not filled with innocent fear. They were filled with hate. He glared at them all, then, to their surprise, shot upright.

Beverly grabbed a hypospray off the table next to her, but Data had leapt off the bed and out of the range of the particle beam. He shoved Picard aside and bolted out the door.

"Security alert on all decks!" Picard yelled. "No one leaves this ship!"