A/N: I am sorry that this chapter is so short, but it is what everyone has been waiting for. The next one should be the last, tying up all of the loose ends. If there is something that anyone wishes to see specifically, R&R and I'll try to work it in.

Ark Chamber, Olduvai

John 'Reaper/Bones' Grimm had finally had enough. To say that this mission had been an emotional rollercoaster was the understatement of the century. The memories of the previous times he had been at Olduvai, the stress and fear of leading green children with no real combat experience into a situation that had given him, a hardened combat vet, nightmares for over two centuries, going in to rescue idiot civilians knowing that there would be none left alive to rescue – but hoping anyway, and above all else dealing with his emotions regarding his former commander and friend had strained his emotional control to the breaking point.

While he had found a few moments of relief from the pressure, his laughing fit at Spock to name one, it really hadn't been enough and none had touched his anger at Sarge, an anger that had lain dormant like a volcano, nothing visible on the surface but slowly building pressure below since he'd found out that the man was still alive. When Sarge casually threw him into the wall on the opposite side of the Ark chamber, after dragging him along like a child's toy, John lost both his temper and control of his instincts over this final insult.

Everyone who had ever met Leonard McCoy would say that the man was someone who frequently lost his temper. He yelled, ranted and was well known for being able to strip the hide off of anyone, regardless of rank, in a matter of seconds. They didn't know about Reaper. They didn't know about Olduvai, or how he'd been changed there. The fact that he never threw a punch at anyone, seeming to avoid physical confrontations even in the midst of a brawl, was to them only to be expected. McCoy was a doctor, a healer, and would never deliberately harm anyone. They didn't know that it was because he knew that he was capable of putting his fist through most solid metal walls. He'd had nightmares of what his fists could do to a frail human body. They don't understand that McCoy loses his temper – so that Reaper WON'T.

Reaper hit the wall and used it to launch himself back at Sarge, never even noticing the large dent in the metal alloy or that he was yelling. This time he held nothing back as he threw a punch at Sarge's head. It didn't really hurt Sarge, even if Reaper had broken the mutant's jaw and shattered teeth, but he was too far gone in his rage to realize it. The blow spun them apart and Sarge shook his head, his jaw already healed but the blow had disoriented him for a moment.

Before he could finish Reaper was back, throwing kicks and punches, gouging at Sarge's flesh as much as he dealt out concussive damage. This was not the controlled but lethal fight of professional soldier against professional soldier that they'd fought before. This was a battle to the death between two immortal predators. Reaper used his smaller body like a hammer, aiming for Sarge's one weak spot – his head, over and over again, absorbing the blows that Sarge dealt out almost without noticing them.

Goat had killed himself by literally bashing his own brains out against the observation window because he'd known that it was the only way he could stop himself. Mac had died when Stahl had ripped his head from his shoulders. John was sure that had been an instinctive reaction for both of them, attacking one of the only two weak spots a mutant had, the head and heart. Reaper used that knowledge now by focusing his attacks on Sarge's head. Sarge would never let him get near his heart, so Reaper didn't even try. Sarge finally managed to grab Reaper's ankle as Reaper's boot scraped the side of his head, and threw Reaper up to the second floor of the Ark chamber.

This side of the Ark portal was even more damaged than the one the two men had torn up before, and Reaper crashed over the railing and into the remains of one of the few free standing computer banks. Being completely impaled through his chest on a piece of metal debris, Reaper didn't notice Sam edge around the corner of the entrance that Sarge had dragged him through. "You son of a bitch!" Reaper snarled.

The bridge crew watched in horror through Sam's killcam as Reaper pulled himself up off of the metal bar while Sarge laughed. He jumped up to the second level. "You always were soft Reaper."

"And you're a fuck-up who shot his own men!" Reaper growled. He ripped the metal bar off the debris and attacked. He swung the bar, but it was only a feint. As Sarge grabbed it, he jumped and punched the back of Sarge's head.

"Great, now they're going to beat on each other," Sam muttered as she tried to get a clear shot at Sarge.

Reaper started at the sound of her voice, and Sarge grabbed him by the leg and threw him onto the edge of the balcony, breaking his back. "It's my turn," he snarled as he kicked Sarge's teeth in. Sarge stumbled back, and Reaper back flipped down to the ground floor. "You got to beat on him earlier!" Sarge jumped down after him.

"I didn't beat on him. I ripped him to shreds," Sam called back. She was trying to get Sarge's attention away from her brother. They needed a distraction, and fortunately for them her defiance worked. Sarge turned and roared at Sam, taking the remark as an insult, making him a perfect target for both twins. They both struck a killing blow in the same instant. Sam shot him through the heart with The Kid's weapons, using the last of those bullets, and gaining at least a small bit of ironic justice for the young man that neither of them had the chance to really get to know.

Throughout his fight with Reaper, Sarge had never fully turned his back on his onetime second, but when Sarge turned to face Sam, Reaper had a clear shot at the back of Sarge's head. Jumping up just enough to give him the necessary amount of height, Reaper slammed his bare fist through the back of Sarge's head and out the front. Distantly, as they fell down and Reaper was left kneeling on the corpse, Reaper could hear himself snap, "Ammo check!" If he'd been in any shape to do so, he'd have smacked himself. It wasn't like he was back with the Hellfighters taking out an insurgent base. With Sarge dead, there were no more monsters to fight. They had won.

"I'm out," Sam freely admitted. "You'll have to check your own rifle though. I'm not about to mess around with your baby." She put just the right amount of teasing into her words, and John reacted very predictably.

"It's not my baby!" John retorted, exasperated at the long time continuing argument. "Taking care of your equipment means that when you need it; it will be ready to use. He stood up and walked over to his sister. "I would think that you'd be glad that I take care of my things. My rifle wouldn't have been mission ready if I hadn't taken care of it."

Sam smirked and handed over Reaper's rifle and utility belt. "John, it's over two hundred years old. Anyone else would have gotten rid of it a long time ago. It's not supposed to be mission ready. It's an antique – and yet you still have it."

"I don't keep it for sentimental reasons. Sooner or later we're going to run into our 'adopted ancestors' and when we do, I want to be prepared," he snapped as he grabbed his rifle from her. He didn't let himself look at the rifle. If he did, his anxiety would show and Sam had enough blackmail on him to last the next two centuries. He didn't need to give her anymore. Besides, he was pretty sure nothing bad had happened in the short amount of time it hadn't been in his possession.

"You think that we're going to run into the aliens who colonized Mars at a minimum of over 10,000, and more likely 100,000 years ago?" Jim interrupted their bickering. "Gee Bones, I never knew you were that ambitious about our five year mission. I wish I'd known about it. I could have helped you with the research!"

"Just for that you're getting a full physical when I get back you ungrateful little brat!" McCoy snapped.

Jim just laughed, having heard a thousand variations of the threat over the last four years. He was also relieved that the most dangerous part of this mission was over with. A few tasks were left, but most of those he could handle for his friend. Bones deserved to relax with his sister and daughter while they were on board. "Get yourselves cleaned up and I'll have Chekov beam you down some clean scrubs. That gunk is NOT touching the Enterprise's clean decks!" Kirk ordered.

"And you think I'm sentimental," Bones groused to Sam, as he led the way back to the showers.