The whole sequence took maybe four seconds from start to finish — an eternity if they had been worried about someone on the other side calmly lining them up in their sights. But with that threat now gone, Anderson had more than enough time to guarantee his aim was lethally accurate. He even had a chance to line up a second merc and take her down, too.

And he wasn’t the only one taking advantage of the situation. All told his team dropped seven of the mercs during their desperate retreat. Only two managed to escape with their lives, making it to the safety of the passage and disappearing around the corner.

Anderson didn’t immediately send his crew chasing after the fleeing mercs. As soon as they lost visual contact with their enemy, pursuing them turned into a fool’s game. Every corner, turn, or branching hallway they’d come across would represent a chance for a potential ambush.

Instead, Dah, O’Reilly, and Lee took up defensive positions guarding the passage in case the mercs came back, possibly with reinforcements. With the only point of insurgence covered, Anderson and Shay were free to examine the bodies.

They’d killed ten mercs in the battle. Now they were picking through their corpses — a ghoulish but necessary denouement to every engagement. Step one was to identify any wounded survivors who could pose a potential threat. Anderson was relieved to find all of the downed figures were already dead. It wasn’t Alliance policy to execute helpless foes, but taking prisoners would have introduced a whole new set of logistical problems to a mission that was already complicated enough.

The next step was to try and identify who they were working for. Five of the dead were batarians, three were humans, and two were turians: eight males, two females. Their equipment was a hodgepodge of military and commercial arms from a wide variety of manufacturers. Officially recognized military units tended to be made up of a single species and carried only one brand of weapons and armor; the

inevitable result of corporations signing exclusive supply contracts with the overseeing governments.

These were most likely soldiers of fortune, members of one of the Verge’s many freelance mercenary bands that hired themselves out to the highest bidders. Most mercs had tattoos or brands burned into their flesh proclaiming their allegiance to one group or another; usually prominently displayed on the arms, neck, and face. But the only markings Anderson found on the fallen were indistinct splotches of raw, scabby skin.

He was disappointed, but not surprised. For jobs where secrecy was important crews often had their markings removed with an exfoliating acid wash, then reapplied after the mission: a simple but painful procedure that was charged back to whoever had hired them. Obviously the group hired to attack Sidon had feared Alliance retaliation and done their best to remove anything that might expose them if something went wrong.

There had still been no counterattack from the enemy by the time Anderson and Shay finished stripping the bodies of grenades, medigel, and anything else useful and small enough to easily carry.

“Looks like they’re not coming out again,” Dah grumbled as Anderson came over to stand beside her. “Then we have to go in after them,” Anderson replied, slapping a fresh power pack into his kinetic

shield generator. “We can’t wait out here forever, and there’s still a chance we’ll find some of our own

people alive down here.”

“Or more mercs,” O’Reilly muttered, replacing his own power pack.

The corporal was only saying what they were all thinking. For all they knew there was another full

enemy squad deeper inside the base, and the two men who’d fled the battle had already managed to warn the reinforcements. But even though they might be walking into a trap, they couldn’t turn back now.

The lieutenant gave the rest of the team a moment to gear up before shouting, “Dah, Shay — take the point. Let’s move out!”

They advanced into the rough-hewn passage, maintaining a standard Alliance patrol formation — the two marines on point up front, Anderson and O’Reilly three meters behind them in the middle, and Lee three meters behind them watching their backs. They all had weapons raised and ready as they made slow but steady progress through the uneven, irregular tunnel that had been bored through the rock. They were officially in a hot zone now, and caution was more important than speed. One moment of careless inattention could cost all of them their lives.

Ten meters in, the corridor turned sharply to the left. The team stopped short at a hand signal from Dah, who crept forward and poked her head around the corner, momentarily exposing herself to possible enemy fire before ducking back. When she gave them the “all clear” they continued on.

Beyond the corner the passage continued for another twenty meters before reaching a sealed security door. The heavy metal barrier was closed and locked. Anderson signaled to O’Reilly, and the corporal moved forward to work his tech magic and override the lockdown codes. The rest of the team assumed standard positions for another flash-and-clear procedure.

“If those mercs are locking the security doors,” Dah whispered to her commanding officer as they waited for the door to open, “then that means they have codes for the base. Someone on the inside must have been working with them.”

Anderson didn’t reply, but he gave a grim nod. He didn’t like the idea that someone inside Sidon had betrayed the Alliance, but it was the only explanation that made sense. The mercs had known the facility was expecting an off-world shipment, and they must have had the proper landing codes to get their ships on the surface without raising any alarms. They’d been familiar enough with the layout to clear out the

upper area and make their way to the elevators at the back without letting anyone escape. And they had to have access to restricted lockdown codes to seal the security door. All the evidence pointed to the inescapable conclusion that there had been a traitor at Sidon.

The door slid open and the team sprang into action, using a flash grenade to blind anyone on the other side, then charging in only to find the area beyond empty. They were now standing in a large square room, about twenty meters on each side. The shiny metal walls, ceiling, and reinforced floor made it clear they were now entering the heart of the research facility. Everything had a sleek, modern feel; a sharp contrast to the rough-hewn natural tunnels they had just passed through. There was a hall leading off to the left, and another to the right.

“I’ve got a blood trail over here,” O’Reilly called out on the left. “Looks fresh.”

“We follow it,” Anderson decided. “Lee and Shay, set up position here.” He didn’t like splitting up the team, but they didn’t know the layout of the base. He didn’t want any of the mercs doubling around behind them and making it back to the elevator. “Dah, O’Reilly — fall in!”

Leaving the two privates to guard the only way out, Anderson and the others set off down the hall on the left, moving ever deeper into the research complex. They passed several more intersections, but Anderson wasn’t willing to split his squad up yet again. Instead, the three of them simply followed the blood trail. Along the way they passed a number of rooms, most of them small offices, judging by the desks and personal workstations. Like the dorms on the upper levels, each had been thoroughly ravaged by gunfire. The killing spree that began on the surface had continued unabated underground. And once again the mercs hadn’t been content to leave their victims where they had fallen, but for some inexplicable reason had dragged them off.

It was five minutes later when they finally came across the source of the blood trail they’d been following. A turian lay facedown on the floor in the middle of a medium-sized room, bleeding profusely from a wound to his leg. Anderson recognized him as one of the mercs who had fled the recent battle. Approaching carefully, he knelt down beside the motionless figure to check for a pulse but found nothing.