"Get her in here." Captain Kirk didn't have to raise his voice to convey the anger he felt at the news that his chief navigator was experiencing memory lapses and was possibly being influenced by an alien he, the Captain, had taken aboard as his guest. He was pacing the Briefing Room, glaring at Sulu, deep in thought.

"I've already asked security, sir," replied Sulu. He stood by the door, watching his captain, feeling a little better now that his concerns had been aired. They didn't have long to wait.

Tamoon walked in with the studied swing of her square hips, taking little steps as if she were nervous. She gave the captain a coy smile. Kirk wasn't impressed.

"Sit down, please," he said coolly, indicating a chair with his hand. She took it without breaking eye contact, smoothing down the flowing silver dress she was wearing.

I wager I'll defeat you, you meddlesome little human, she thought to herself, and it will be a pleasure. Shanna told Tamoon all about you. You think your good looks can achieve influence over any female? Well, I'll be the one to prove you wrong. "Yes, captain? Why have I been brought here?" She gave her two guards a look of trepidation as they moved to stand at either side of her. She put her bare yellow arm on the table and rested her sharp chin on the back of her hand, pouting her lips in innocence.

"What have you done to my navigator?" Kirk asked sharply, leaning over the table and placing his hands down opposite her.

Tamoon raised her thick, bushy, orange-white eyebrows. "Me, captain? I haven't done anything. I rescued him from Senrug on Triskelion and brought him back to you. Am I being accused of something? I was only trying to help."

Kirk ignored the blink of her wide eyes. "Since you've been on board, Ensign Chekov had had a loss of memory which seems to focus around the times he spends with you. How do you explain that?"

Tamoon placed her head on one side and raised her shoulders in a non-committal shrug. "I'd say he was lying, Captain. Oh, don't get me wrong, Pasha's very sweet. I think he rather likes me. But I can't seem to shake him off. I think he's becoming a bit obsessed." She looked up at the captain and smiled sweetly.

Kirk pursed his lips. "The last time I saw you together on Triskelion he was telling me how he was glad to be rid of you and you were tied up on the floor of his cell. He didn't give you a backward glance. He couldn't wait to be rid of you. That doesn't sound like obsession to me." He remembered Chekov's relaxed grin as he stood, arms folded, leaning against the wall of his cell as he waited for Kirk to let him out. There had been triumph in his eyes, not regret.

Tamoon remembered the events with humiliation. "There was more to his stay on Triskelion than you realise, Captain," she said darkly, her husky voice dropping even lower.

Kirk heard the change in her tone. "Do go on," he pressed, trying to seize the moment.

Tamoon saw the parry and side-stepped it, regaining her composure. Her eyes widened again. "It would be immodest of me to reveal details, captain." She tried to give a girlish giggle. "Like I said, he keeps coming after me, not the other way around. What's a girl to do? I'm sure you and Shannah had a similar time."

The image of the beautiful drill thrall leapt into his mind. He remembered her thick silver green hair and slim, delicate body. As a fighter she had not been strong, but she had been agile and had a seemingly limitless stamina. It had pained him to leave her. There were not many girls who had really made him think twice about returning to his ship, but she had been one of them. He shook his head. "Shannah has nothing to do with this."

"She missed you, captain," Tamoon continued, seeing she had made an effect. "She was devastated when you left. She joined the rebels when the war began. She fought and died heroically." She tried to add a note of tragedy to her voice. The truth was, Senrug remembered, Tamoon had begun to hate Shannah and her rebellious ways even before the war had broken out. Senrug soon identified her as dangerous. She had to go. Tamoon had been the tool.

"Died, you say?" Kirk straightened up, shocked at the news.

"Oh, yes. I'm sure your name was on her lips, captain. You were her inspiration. You inspired us all," said Tamoon wistfully. She was sure she could appeal to his vanity.

Kirk's instincts were alert. "And what side were you on?"

"With the rebels, of course," she replied, looking hurt. "Senrug had to be defeated. She didn't want anything to change on Triskelion. You offered the Providers the possibilities of freedom and education. She preferred the endless abyss of Chance."

Kirk walked round the room and seated himself on the edge of the table next to her. Tamoon got up, seeing the physical challenge that he was attempting. You pathetic man, she thought smugly. You have no idea that I am Senrug. If I had not taken Tamoon's body I could have read your thoughts and dispatched you long ago.

"It sounds to me that you admired Senrug, Tamoon," he said, leaning in conspiratorially.

Tamoon gave a half smile. "I had to know my enemy, Captain". She moved over to the other side of the table. She didn't want to admit to herself that he actually intimidated her. And that's where I can help you. I can see you're suspicious of me, so I will prove my sincerity to you. I know Senrug is down on the planet somewhere. I can help you to find her. I was her personal thrall before you released us. Hasn't that got to be worth something?"

Kirk looked back at her sceptically. "And how would you propose to do that?"

"She had a base of refuge in the old city. She always said that if she ever faced attack she would go there."

"Tell me where it is," he fired back. Claims of sincerity were one thing – what he needed were hard facts.

"I don't want to go back to Triskelion, captain," she said, a scared look pulling at her thick lips. "You've given me an outlook I never possessed before you came to us. I want your assurances that you won't send me back. I'm afraid. You're accusing me of influencing your navigator – the one all our stories say will betray you. It's not me you've got to be worried about. Senrug has affected him somehow. If you find her, then I'm sure you'll get the answers to your navigator's problems."

Kirk took in her easy, confident manner. She was bargaining with him. She looked anything but scared, but it nagged him that she did seem to be making sense.

"I need Chekov in here," he muttered. He didn't – couldn't – believe that his navigator was lying. Perhaps Senrug had got to him somehow on Triskelion. He walked over to the wall and hit the communicator panel.

"Kirk to Spock."

"Yes, Captain."

"Send Mr Chekov down to Briefing Room 1, please."

"Mr Chekov is not here, sir."

"Then where is he?"

"He advised that you had asked him to assist Mr Scott in Auxiliary Control."

"What? No I didn't…" He quickly reset the controls. "Kirk to Auxiliary Control."

Silence returned his call. He tried again. "Kirk to Auxiliary Control. Come in Scotty." Still nothing. Perhaps they had left. He was about to try intra-ship when the ship gave a violent lurch, sending the gravity controls into chaos. The lights dimmed and everything became weightless for a second before the system reset and pulled everything back down onto the deck with a thump. Alarms went off all over the ship. We've been attacked, was Kirk's immediate thought. He reached for the communicator panel again, but Spock had got to his controls first.

"Captain. Helm control has just been diverted from the Bridge. We are attempting to locate the source. Warp three had just been initiated."

He hadn't expected that. "Damage report?"

"Lieutenant Uhura is working on that now, Captain."

"OK. Meet me down in Auxiliary Control."

Kirk spun round to Sulu. "Get back up onto the Bridge and try to get the helm back and drop us out of warp. Do all you can. Find out our trajectory." Sulu nodded. He was always impressed by Kirk's focus in a crisis. It enabled him to follow orders with confidence.

"That will take longer without Chekov, sir." The Russian's skill and knowledge always outshone any of the other navigation team and things always happened a lot faster when he was around.

"Where the hell is Chekov anyway? See if you can find him. Call up the duty navigator and get him started."

"Yes, sir."

Kirk watched as he headed out of the door. He spun back to Tamoon and the guards.

"Miss Tamoon, please return to your quarters. This will have to wait. Lt Branswell will escort you. Donner, come with me. Let's get down to Auxiliary Control".

Kirk and Donner raced out of the room and ploughed down the busy corridor. Crewmen hurried out of the way as they pushed past. They slid down the rungs of the ladders between decks to speed their descent before landing heavily at the bottom, dashing past Engineering and on to Auxiliary Control. The door did not slide open as they stood on the threshold. Kirk opened the hatch to the manual lock in the wall next to the door and pulled the emergency release handle. Nothing happened. Something serious must have occurred for the controls to be dead. Spock appeared just as he was trying to open the panel to the electronics. Kirk stepped aside to let him try the heavy release handle he had just failed to move, acknowledging the Vulcan's superior strength – but to no avail. The door remained firmly shut.

"I'll have to phaser it open," said Donner.

Kirk pointed to the circuitry. "Remember to just target the actuator."

Donner nodded. He raised his phaser, steadying it with both hands and gave one short, precise low power blast. He flinched as the controls crackled and smoked. The door slid slowly open. Kirk gestured silently to Donner to enter the room. He nodded in reply, tense and at the ready to sweep the room. He was barely through the door when he fell back heavily into Spock's arms with a cry of pain, caught in the shoulder from the stun blast of a phaser from inside the room.

"Get down!" Kirk yelled to Spock, pressing himself up against the wall as another blast shot through the door and struck the bulkhead opposite. He leaned forward slightly to shout through the door as Spock lay Donner gently down against the wall, checking him over for wounds.

"Scotty! Chekov! Are you in there? Are you alright?"

At first he couldn't hear anything but then he thought he caught the sound of muffled cries as if someone was gagged and trying to call out.

"Zamolchi!" came a vicious hiss from inside followed by a dull thud.

"That's Chekov," said Kirk to Spock in surprise. "Chekov, are you in there? Are you alright, Ensign?"

"Poshyol ty, ili ubyu tebya." He voice sounded clear and threatening.

"What's wrong with him? Why is he speaking Russian?" asked Kirk, turning to Spock.

The First Officer raised an eyebrow in curiosity. "We must endeavour to find out, Captain," he replied smoothly.

"Ensign, we're coming in. Please try to stay calm. Don't shoot," shouted Kirk through the door. He stepped over the threshold, his hands splayed in a gesture to show that he wasn't armed. He wasn't sure that he wouldn't be shot just like Donner, but he hoped that Chekov's ingrained respect would make him think twice. As he walked into the room he stopped in shock, unable to believe what he was seeing. On the floor, up against the main control panel, sat Scotty, bound and gagged with insulating tape and with a fresh, deep cut to his temple. He had obviously been hit hard as the wound was still bleeding. The blood had made his hair sticky and had soaked into his uniform collar. Chekov stood beside him, a phaser in his hand. He was holding it against Scotty's head with a steady grasp. Kirk found it difficult to judge his expression, so different was it from his usual demeanour. Although he seemed calm enough, he was pale and his breathing seemed thready. There was a heady determination in his eyes that Kirk realised immediately made him extremely dangerous. A thought crossed him mind that perhaps he was drunk. Chekov's Standard was well known to deteriorate the more he drank.

"Chekov, what have you done? Put the weapon down." Kirk started softly, casting a glance at Scotty. The engineer looked dazed from the recent blow but aware enough of his surroundings to acknowledge the captain's look.

"Nyet. Uberyaityes ot syuda!" The reply came back abrupt and angry.

"Chekov, we don't understand. You're speaking Russian. If you've been drinking, then we can sort this out. But I need you to put down the phaser."

Chekov scowled back at him and swallowed hard. "Go away," he ground out disdainfully between his teeth. "Or I kill engineer."

Kirk stood his ground, showing that he wasn't to be intimidated. "You know I won't do that."

Chekov gave a thin smile that did not extend to his dark, watchful eyes. "Kompyuter, zaklyuchi dvyer."

The door slid shut at his command before Kirk or Spock had any chance to react. Kirk didn't even bother to turn round or try the door. He knew it had been locked. He raised his eyebrows. "Well, well, Ensign. I knew you were good, but I didn't know you were that good. Overriding the emergency back-up controls and security protocols… that's something I didn't know we'd taught you."

Chekov raised his chin with an arrogant stare. "There's a lot you don't know about me, captain."

Kirk smiled wryly at the reply. He hadn't yet decided how he was going to handle the young man. He wasn't behaving in a normal fashion that he could easily react to. Kirk needed to know more about what was going on before he could make a decision. He changed his mind. He didn't look drunk. His eyes were clear and his hand was unshaking. But it was the wild gleam in his eyes that disturbed the captain the most.

"Chekov, this isn't you. What you're doing here – it's all wrong. I know you to be a loyal officer and a good person. Put the gun down."

"Loyalty and goodness have nothing to do with this," replied Chekov stonily.

"So I see." He nodded his head towards Scotty. "Let him go. You have nothing to gain by keeping him here."

Chekov shook his head, a sneer pulling at his top lip. "No, Captain. That would be foolish. He is my security against you."

"But he's wounded. Let Dr McCoy have a look at him."

"No."

"Ensign, why are you engaging in this unusual behaviour," asked Spock, hoping that a double line of questioning might distract the ensign and put him off guard.

Chekov's eyes flicked over him. "We need to go to Cyliss. I take us there."

"To Cyliss?" asked Kirk taking a step forward. Chekov pushed the phaser harder against Scott's head with an admonishing look to the captain. Kirk stopped. "That's the Providers' home planet. You don't know where that is."

"Again you are underestimating me, Captain. We passed it about four months ago. I mapped it in Talliss System. Clearly I remember it."

"Yes, no doubt you do," muttered Kirk, casting a look at Spock. Normally his navigator's near photographic memory was a boon to him on the Bridge – this time it was a curse. He was starting to detect an arrogance and overconfidence in him and that this pride could be a means to unlocking the information he needed.

"Why do we need to go to Cyliss, Ensign? Who ordered it? Who are you helping?"

"Senrug herself personally asked me," he said, a gleam of obsession entering his eyes. "She trust me. She is beauty itself, but she is under attack from those who do not understand her. She torments herself. I have to help her. I need to do this."

Kirk thought he got the gist of his navigator's broken Standard. "And where is she? I need to talk to her. She's fighting an evil war and I think you've just become a pawn in it. Whatever she's told you, whatever she's promised you, it isn't true. I need you to understand that."

"She not promise me anything," replied Chekov, a feverish brightness flushing his waxy cheeks. "I serve her willingly."

"Then what does she want?" asked Spock.

"Glorious mission to return to her people and to rally them to ways of those they banished. To take this ship to Earth and to take its people for the Games. You offered up our crew last time, Captain. When people of Cyliss see possibilities of whole human race, they not refuse."

"The Federation will never let that happen. She must know that," countered Kirk.

"With starship, odds are good."

"So you're betraying me after all."

During this exchange, Kirk had moved closer. He had manoeuvred himself to a position from which he could gain an advantage. He was now within striking distance. Chekov's ecstasy had distracted him. He had let his phaser fall from Scotty's head. Kirk saw his moment. With a well-practised kick of his right leg he threw his body forwards and down, striking out at Chekov's phaser. He knew that he had to be lightning quick. Chekov was known for his accuracy and unfailingly quick eye. His foot struck home. His aim was good but Chekov's grip on the weapon was firm. As Spock moved forwards to disarm him, he fired the phaser with an eerie calmness. If Kirk had not timed his ascent from a short roll with precision, the shot would have landed true. Kirk lunged at the young man, crashing into him and bringing them both down onto the floor. Chekov however was winded was but not subdued. With a heave of his arms he pushed the captain off him and rolled over, bringing himself over the top and straddling him. He lashed out swiftly at Kirk with his phaser, hitting him in the face. Kirk fought against the explosion of stars in front of his eyes. He lunged out wildly with this arm almost instinctively. He felt it connect with something hard and heard the phaser skitter across the floor out to one side. His vision cleared for a second. With horror he saw Chekov pull out a knife swiftly from his boot. He raised it above his head with both hands, ready to plunge it downwards. Kirk took in his parted lips, closed eyes and intoxicated look as if he were making a sacrifice. The knife flashed brightly like descending lightning. Chekov's expression suddenly changed. His eyes opened and widened in shock. He threw back his head, crying out in pain. Slowly he fell forwards, the knife falling from his limp grasp onto the metal deck with a sharp clatter. Kirk caught him, pushing him to one side as he fell across his shoulders. Spock looked down at him, stretching his hand as if dissipating its energy.

"Vulcan neck pinch?" asked Kirk breathlessly, struggling to sit up.

"Indeed, Captain," replied Spock simply. He offered him a hand to pull him up.

Kirk took a gulp of air and grasped the hand gratefully, dusting himself down and stretching his back. He rubbed his nose gingerly. "That boy can kick a punch when he wants to." He looked down at Chekov. His body lay twisted on the floor, but his face seemed calmer, somehow more recognisable again. "What is going on with him?" he mused aloud.

A stream of muffled noises rose up from the other side of the room, grabbing his attention. "Oh, Scotty. I'm sorry." He hurried over and with Spock's help, untied the engineer's hands and gingerly pulled the thick tape from his mouth.

"…the lad's gone mad. He hit me over the head and tied me up. He wouldnae stop talking in that heathen tongue of his. I had nae idea what he was saying. He's been fiddling with the controls. He's put us into warp without priming the dilithium matrix. I thought he was going to blow my engines apart. He may be an excellent navigator but he makes a terrible helmsman. When this is over, never ever, ever let him take over the helm, Captain."

"Don't worry, Scotty. He's going straight to a secure unit in sickbay. Bones will find out what's wrong with him."

Spock moved over to the controls, assessing them before touching anything. Red lights were flashing over the consoles in a firey dance. "Impressive," he murmured. "I believe he has tied the helm into the antimatter system. He has also made some changes to the navigation controls. At first glance I'd say he has hard-wired a course into the plotting computer. This could take days to resolve safely, captain."

This was not the news that Kirk had wanted to hear. "Scotty, are you up for making a start after Bones takes a look at you?"

Scotty nodded firmly. "I captain. It's just a graze." He hauled himself stiffly to his feet. "Anything to get my engines back to normal."

"Bridge to captain Kirk." Uhura's voice sounded urgently across the intercom.

Kirk stepped over to the panel and thumbed on the system. "Kirk here. Go ahead."

"Captain, a message has just been sent from your location, sir. It looks like it was on a delayed timer. Destination I extrapolate would be… the fourth planet in the Talliss system. It was sent on a priority carrier."

"What does it say, Lieutenant?"

"It's not in any known Federation language, Captain, but I thought I recognised it. I have tied it into the tricorder readings I took on Triskelion at the arena. It may take a while but I'm sure I can translate it."

"A message to Cyliss, Captain?" asked Spock.

"I would assume so." Kirk bent down and picked up Chekov's phaser, disabling it with a push of his thumb. "Spock, get Bones down here. Let's get Donner and Scotty to Sickbay."

"And Ensign Chekov, Captain?"

"Yes, and him too. I want him in a secure unit. He can wake up in his own time. He moved over to the cross-circuited controls in the door security panel and began to unpick Chekov's handiwork. Uhura would translate the message as best she could, however he felt that he probably already knew the content. It would be a call to arms. Even if Scotty got the helm back on line that minute they now had no choice – they had to go to Cyliss. The Providers had to be stopped.