Quis custodiet ipsos custodes?

Shepard could see the expanding bubble of flame and debris in his mind's eye, following the path of least resistance, moving along the grid of corridors ahead of the structural collapse. Then, he didn't need to visualize it anymore; over the engineer's shoulder he saw the approaching flame for all of a millisecond; no time to run, no difference for it to make. He saw the shockwave begin to pulp the man a nanosecond before he was incinerated.

Then the bubble hit the door. The shockwave caved it in, made it bulge outwards slamming him backwards, knocking him from his feet a second before the searing heat began to make the door glow red, at temperatures that would have melted his armour and stuck him to the door as a piece of meat sticks to a frying pan while it chars and blackens. He felt more than he heard the rumbling, the groaning of the bunker network as it spasmed and fought a seizure that would cause it to collapse. They were at least twenty metres under reinforced concrete and suffocating earth; there would have been no hope of rescue even had this not been a warzone.

The pressure behind the door built up, the force straining at the sealed steel door, cracks appearing in the glass and disappearing again as the viewport melted in tandem with its door, the rumbling reached a bone shaking crescendo and the door-

Held, just, as the rumbling subsided, and the pressure reduced, having found other outlets, and the door cooled from white hot to a tamer red. But the damage had been done. With a groan, the door broke its seals and fell away from its hinges and ponderously began to topple down towards Shepard. He hastily scrambled out of the way and got to his feet, and stood there, staring at the back of the door in morbid fascination. Outlined against the charred and blackened metal, was the shape of the dead engineer; all that was left of him.

Past the door, the entire network that had contained the comms hub had collapsed, killing all of the batarians inside-those that hadn't been incinerated, which would have been most of them. Shepard turned to see his five remaining men looking at him gravely, seeing the mark on the door, and how Shepard stood alone, and needing no explanation. He sighed.

"There wasn't time. It was him, or all of us." He said, his voice more apologetic than he felt, but now that their mission was all but over, it was time to tune down his callous attitude-

"Lieutenant McCarthy, come in." The voice of Command, presumably. Shepard turned and gestured to the Service Chief, who was still technically the ranking officer.

"McCarthy's down sir, we've completed the primary objective, but we've taken fifty percent casualties."

"Understood, chief. Good work. Move up to the surface and link up with the main force to clean up."

"Yes sir." The Chief disconnected, as did Command. Shepard motioned to the other three squad members to go and scout for a way out, leaving him, the Irishman, and the Chief.

"-peat, can anyone hear me? Command? McCarthy?" A static ridden voice called out. It sounded like Kyle's voice.

"This is the Chief. I have command of the squad. What's your status Major?"

"We need an assist urgently! These batarians, there's something wrong with them-and it's happening here at the engineering hub. When you blew the command centre, they all went berserk-and that's compared to how they were before! We've been trying to push through to the objective, but we're getting mown down-" The signal cut off. Automatically, the NCO looked questioningly at Shepard, who brought up his Omni tool.

"Get word to Command. I'll see if I can work out their position."

"Command, this is the Service Chief. Major Kyle requests an-"

Shepard severed the signal. "Sorry, Chief. There's been a development. I've found the genuine command centre. They're having to broadcast what I assume is a rally or retreat signal from there now we've taken out the antenna. We need to hit them so they can't come back from this; we can't help the Major."

It would be a mistake to construe this as devotion to the greater good, this drive to get the job done and ensure that the enemy would stay dead. It was strict professionalism, in part, but Shepard understood that if the batarian Command escaped, they'd only be back, and they'd only have to be dealt with again. And now that the 95th had experienced the bastards; they'd be first on the list for whom to deploy. That was how Command thought. And next time would only be worse, and bring a greater likelihood of death.

Shepard didn't fear death, but his survival instincts were intact; he wouldn't just lie down and let it take him, he was a slave to Darwinism. They had to eradicate the threat now, deliver a coup de grace, or it could come back to haunt them and the men that died now would die anyway, and might be joined by Shepard.

"What are you talking about? We've been given an order."

"Not yet we haven't, so we can't disobey. That's why I cut off Command."

"We're helping the Major, Shepard. Where's your loyalty to the squad?"

"Not interfering with my thought processes. You need me to keep these men alive, I'm the only one who can save them, and Kyle, and I'm the only one who can bring about a true end to this mission. I can do lots of things, Chief. That doesn't mean I get to choose. I have to take the long view instead."

"I'm not going with you. I won't betray my own men."

"They aren't yours. Remember what I told you?" Shepard drew his pistol, confident that it would be working again.

"What are you doing?" O'Reilly burst out.

"Stand down, Private. I don't want to kill either of you, but that doesn't mean I won't. Follow my orders."

"I can't. This is wrong." The Chief said. O'Reilly stood his ground.

"There is no good system of morality for situations like this, Chief. It's just grey. That's all it ever is."

Who to kill? The Chief was more likely to cave if he shot the Irishman, but that was because he was a coward, and so would be less useful in a fight. O'Reilly would be a better asset, and he was less of an idiot.

"O'Reilly. You'll see. I'm saving more lives this way. Stand down. Please." The man's face twisted with the agony of indecision, as the Chief looked at him anxiously. Shepard raised his pistol, pointing it at neither of them. "I'll let them put me on trial if they want, if they disagree, but I'm right, and sacrifices have to be made."

The Irishman sighed. "I'll have to hold you to this."

"Thank you."

The Chief panicked, and drew his own pistol. "Private, what are you doing?" He brought up his pistol to aim it at Shepard-

And Angel Eyes shot him in the face, without so much as a blink. The Chief went down without a sound. Shepard sighed and holstered his pistol, then gestured to O'Reilly and they trudged heavily up to find the scouting party. They ran into them after a minute.

"Where's the Chief?" Shepard began to answer, but O'Reilly cut in.

"Stray batarian got him. We weren't fast enough."

Shepard nodded, apparently in agreement, but the Irishman correctly interpreted it as thanks, for making his life a little easier for now.

"We've got some new orders. Let's go take out these bastards' commanders."