They moved quietly through the brush, McKay concentrating harder than he ever had in his life. Too soon and they might miss the ambush. Too late and Sheppard would be gone again. He felt ready to jump out of his skin with tension and he hadn't missed the looks the other three were giving him.

"You sure you're all right, McKay?" Sheppard asked.

The scientist swallowed hard. It was now or never. "I think I heard something."

Ronon and Teyla stopped and looked around. "I hear nothing," said the Athosian woman.

"Me either." Ronon frowned.

"No, I'm sure I heard something." McKay pointed. "Over there."

Ronon and Teyla split up, circling around behind the area McKay had indicated, and there was a brief sound of fighting, then half a dozen men were herded into the clearing, Kolya in the lead, their hands laced behind their necks. Ronon and Teyla had their guns on the captives and Sheppard was already grinning wolfishly at the thought of taking Kolya back to Atlantis when McKay pulled out the zat gun and fired. Kolya went down screaming and Sheppard turned a shocked face to McKay. He was shouting something and throwing himself at the scientist but McKay sidestepped him and fired another shot at Kolya. Not content with his death, McKay fired a third time and Kolya vanished from the universe.

The other Genii cowered as Sheppard wrestled the gun away from McKay. "Rodney? Rodney!" He slapped the scientist across the face and quailed as McKay met his eyes. Sheppard had too much darkness in himself not to recognize the sight of it in another person, but he would have bet everything he would ever own that Rodney McKay didn't have a dark side. To see it in him was a shock so great that for a moment Sheppard felt light-headed. He held onto McKay's tactical vest and snapped harshly at Ronon and Teyla, "Let them go." The Genii scrambled off and Sheppard closed his eyes, trying desperately to calm himself. "Ronon, Teyla, go back to Atlantis. Tell them we ran into an ambush but we beat off the attackers. And that McKay and me will be a little longer." He glared at them fiercely. "And don't tell them about Kolya."

They nodded and left without a word and Sheppard pulled McKay down to the ground. He felt worse than light-headed now, he felt sick, and he had to take a moment before he finally got out a single word. "Why?"

McKay was lost in the memory of a thirty seven year old man with the mind of a child. I love you, Rondy. I love you too, John. There were tears in his eyes as he finally said dully, "I had to make sure he could never hurt you again."

Sheppard was rocked by the answer. He knew McKay had seen what Kolya did to him, feeding him to a starving Wraith. All of his friends had seen it, but he was the one who had suffered it and he had assumed he was the only one with nightmares. A wave of guilt washed over him as he thought of McKay being haunted by what had happened and now he choked out, "God, Rodney, I'm sorry…"

McKay looked up so suddenly Sheppard was startled. "What are you sorry for?"

"Well…" Sheppard floundered. "You...I didn't know what Kolya did to me was bothering you so much. I still have nightmares about that Wraith coming at me…"

"So that's what your nightmares were about?"

Sheppard didn't notice the odd form of the question. "Yeah. Not often, but sometimes I wake up in a cold sweat, thinking I'm about to be fed on again."

McKay closed his eyes. "I wish you had told me."

"Well, if I'd known you were this upset about it, I would have." Sheppard's voice turned hard. "But killing an unarmed prisoner, we don't do that no matter what they've done."

McKay wrapped his arms around himself. "I don't care. You can send me back to Earth or throw me in the brig or shoot me right here, and I'll still say it was worth it. You're safe from him now. That's all that matters."

Sheppard frowned, his mind racing. McKay's reaction when he came into the cafeteria, the beads, the fierce alertness the scientist had shown from the moment they came through the gate onto this world...And just how had McKay known about Kolya and his men? Sheppard hadn't heard anything, and he couldn't believe Ronon and Teyla had missed a sound the scientist picked up. "Rodney," he said slowly, "what aren't you telling me?"

For one brief moment, McKay considered telling Sheppard everything. The constant worry and sorrow, the pride whenever Sheppard mastered a new skill, the joy of making him happy in their home on Earth. The times his friend had driven him crazy or scared him to death, the nights he had held Sheppard in his arms and soothed his nightmares...McKay sighed. He couldn't talk about these things. They were reflections of Sheppard's soul in a time that was never meant to be. The scientist got to his feet. "What's done is done, John. All I want to know is what you're going to do about it."

Sheppard stood too. "There's nothing to do about it. We don't even have a body." He weighed the zat gun in his hand. "I didn't know you had one of these."

"I acquired it recently."

"I see." Sheppard tucked it away in his vest. "I think I'll hold onto it."

"Fine with me." McKay shrugged and started back to the gate. "I don't need it any more."

Sheppard fell into step beside him. "You know, McKay, if you ever want to talk…"

"I know." McKay turned a searching look on his friend. "The same goes for you. If you have a nightmare, you can always come bang on my door. I'd rather get up than think you're dealing with it by yourself."

Sheppard smiled a little. "I'll keep that in mind."

They reached the gate and Sheppard dialed Atlantis, walking through to find himself confronted with a furious Rodney McKay. "Where is he?"

Sheppard spun around to see the gate shut down, then turned back. "McKay?"

The scientist sprinted up the stairs and dialed the gate. The vortex shot out and he ran down the stairs and into the wormhole. Sheppard dove in after him and they came out on the other side almost simultaneously.

McKay scanned the area. "He couldn't have gone far…"

Sheppard grabbed the scientist by the shoulders and shook him. "You want to tell me what's going on?"

"He said he came back to set things right." McKay was still seething. "He came to my quarters and said something had gone wrong and he had to fix it. Then he shot me with a zat gun and tied me up! Did he go with you?" Sheppard nodded and McKay's voice went up a notch. "And you couldn't tell it wasn't me?"

"Well, if he came from the future, he was you!"

"No, I'm me!"

"I hate quantum mechanics," growled the colonel. He fell silent, then said slowly, "What do you think he came to fix?"

"I have no idea." McKay was calmer now, thinking it over. "It must have been something pretty terrible for him to risk changing the timeline." He snapped his fingers. "And he must have succeeded. That's why he's not here. Once the past changed, his future never happened, so he just disappeared. It has to have been this recon. What happened?"

Sheppard blanched. "We captured Kolya and his men. The other McKay warned us of an ambush. Maybe...maybe someone was killed the first time around." Their eyes locked as they considered whose death would have made McKay desperate enough to go back in time and Sheppard went on with difficulty. "I let the men go. McKay...the other McKay…he used the zat gun on Kolya. Three times. Kolya's gone."

The scientist considered this, then said flatly, "I'm glad I'm the one who got to kill him."

Sheppard felt a chill as he saw the darkness in McKay's eyes and suddenly he wanted nothing more than to get away from this planet. "I'd rather not think about it. Let's just go home."