Draco stretched, taking a few precious seconds to rub his neck and rest his eyes. I'm tired of that map.

The view never changed, mostly water. Land from the south jutted up into the lake or sea or wherever it was, a small bump ships moved around. A gentle curve of land starting in the east and gently curving to the north. A few islands - including one that looked vaguely like a dolphin. The Bludger bobbed gently, roughly halfway between the invading land to the south and the northern shore. A good position to monitor air traffic. Hermione said she'd seen it before, but Draco didn't recognize it and Harry had asked them not to investigate.

Which was fine with Draco. He had more pressing concerns.

Dozens of brooms moved across the map, but the voices around him spoke calmly and softly. This simulation had just started its third hour: they'd gotten up early on a Saturday morning so that they could do a full day.

Like Muggle Movie Night, The Muggle Broom Simulation (as it was now called) had proven popular. Harry had opened them up to other students and asked each of the Bayesian Conspiracy Members to run groups through. Draco still didn't know how to create or operate a scenario, but once you started it the spell took over. By now over twenty groups had finished the basic simulation that the Conspiracy ran the first night. That left hundreds of students who wanted to try. A spectator area had been set up, which helped now. Since people witnessed other missions, the adjudicator didn't need to explain every detail every time. Several special training sessions had been run to explain things to the entire crowd, and there were a few variant simulations, to add to the surprise.

Harry had warned this new scenario was much more complicated.

Draco couldn't disagree.

Draco couldn't see the spectators, but The Bludger usually drew a crowd. Each crew named their own ship, and kept tallies of their wins and losses. So far this morning they'd dealt with several brooms trying to take advantage of blind spots, a large broom attack, and an accidental fire had rendered them blind for several minutes before their map had been restored. Now several boats had started an assault against the Doppleganger Defense. They'd been small boats - practically invisible to radar - but The DD was vulnerable to even the smallest boats.

It was another Skysweeper, after all.

"How long until our brooms reach the DD?" Draco asked, eyes still closed. He could remember the rough broom positions. The Doppelganger Defense was off to their west, and the brooms were on it. Green brooms were converging on their position. Draco felt like the map image had been burnt onto his retina.

"Five minutes," said Daphne, who was running communications for today.

"Contact 4474, presumed red," said Gregory.

Draco opened his eyes and looked at the map. 4474 had just taken off from the mixed use northern-central airbase. The clock showed 10:17:15. Barely three hours into the simulation, five hours to go. Harry had explained that this scenario studied fatigue on decision making. This was meant to be tiring, Draco felt exhausted already. This was another hassling run, probably. The enemy almost never directly attacked, not without a local force advantage, but they'd send out brooms to divide forces or probe for weak spots. Right now the Bludger had sent its brooms to help the DD, so it didn't have great defenses.

Draco sat in the big chair today.

An automated voice, sounding like a middle aged woman said, "Bludger, Request information on P-3." The simulation had gotten more complicated. Now the team also fielded requests from the rest of the fleet, as well as getting support from them. Draco scanned the map for the P-3, which was apparently a command broom carrying equipment similar to a skysweeper. He'd been incredulous last week when they'd been added to the scenario, that Muggles had flying command centers. But Harry assured him they did.

Since the P-3 flew it could scrye farther than the Bludger. It was probably coordinating the red brooms. Draco didn't see it on the map.

"Southern view? That P-3?" The broom had been seen in the south west … fifteen minutes ago. Was it that long? Draco had a rough feel for how fast it could go, but that covered a large portion of the map.

Hermione ran the Southern view today. "It's been out of our range for over eight minutes. I've got last known coordinates. Let me see ..." As Hermione spoke the simulation continued asking about target numbers. They'd complained about that, but apparently that was realistic. The simulation didn't listen to them. Just gave information. Draco saw Hermione's notation appear on the main map.

"Comms, relay the information back on the P-3," said Draco. Daphne acknowledged the command and Draco could forget about this. A few seconds later Daphne spoke up again.

"DD is firing on incoming boats and taking fire. Still requesting support." Draco saw a red broom disappear near the DD. He almost cursed, it would be at least five more minutes before they could support. A broom appeared at the edge of the eastern coast, well inside the outer circle. It had probably been flying low to avoid radar. A second. Both red. Draco didn't need to do anything, the team ran smoothly.

"New targets," said Hermione. "4802 and 4845 coming in from the east. ETA five minutes." They'd seen dozens of hassling sorties over the last two sessions. If these two brooms followed the pattern, they'd rush towards the Bludger for a few minutes, then break off. Two brooms weren't a serious threat, but could provoke an incident if Draco over-reacted. Eventually one would try something … and given the current attack on their sister ship now might just be the time.

"Captain," Gregory said. "4474 hasn't acknowledged my challenges."

Draco looked at the map. 4474 still had a red question mark. Draco recognized the path, it was used by the grey brooms to go from the mixed use northern airfield to the mixed use southern airfield. But enemy planes sometimes hid in the shadows of the larger skybuses.

"Comms, confirm." Draco said. Draco could hear Daphne's quiet voice talking.

Draco noticed that the red brooms in the east closing in, still a few more minutes away from where he could threaten them. Draco looked at the map and focused on the broom bearing down on them. This didn't feel right. He couldn't do anything about the other brooms. Not yet.

"What do we know about 4474?" Draco asked.

"Uh, took off three minutes ago. No scheduled flight at that time, which is why simulation presumed red. Following the standard path for grey brooms, that's why I checked." Gregory hesitated than offered his opinion. "A gutsy hassle run, maybe?"

Daphne started to say something, but the automated voice cut her off.

"Bludger, be advised brooms 4850 and 4292 breaking off from Doppelganger Defense and targeting you." The voice sounded matronly, like an officious bureaucrat pleased with herself.

"It's not responding," Daphne said.

"Those two breaking from DD to us have priority," Draco said, and he could see the readouts indicating that Neville had moved the shields to cover the brooms breaking away from the DD towards them. Blaise was also bringing weapons to bear. He watched them, they'd be here in a few minutes. That was too much of a coincidence. Two brooms coming in from the west, two coming in from the east, and one from the north.

"ETAs on all inbounds?" Draco said. Numbers appeared on all the brooms, All the brooms would hit the red circle within a minute or two. He couldn't deal with them all.

Draco started to speak but the simulation started as well, Draco raised his voice. "Declare a no fly zone, our red circle, effective now. Order all brooms away. Weapons Free. Keep shielding the pair to the west."

The bridge responded with a flurry of voices. The two eastern brooms kept approaching, but the western brooms were veering south. They might clip the no-fly zone, it would be close. The northern broom stayed unchanged.

"Ops, What is 4474 doing? Anyone?"

"I … I can't tell," said Gregory. Hermione flicked her wand at the map. Then again.

Gregory found his voice "Got it. Descending. It's an attack run!"

"It's ascending," said Hermione, her voice rising in tone just like Gregory's had.

"Which is it?" Draco said. The ETA counter was timing down. "Shields cover 4474. Weapons, you are free to shoot the others, but hold off on 4474."

"Something is weird about it," said Gregory and Hermione quickly agreed but they were both working their wands. The ETA timer was counting down.

"Covering 4474," said Neville. The timer was at five seconds. Draco watched it counting down to four three, two, one, zero, the broom was flashing as it crossed the red circle. It could fire on them now, and the closer it got the worse it would be.

Neville, staring intently at his readout, spoke up "Thirty more seconds and our shields won't matter."

They'd learned early on that, at least for these type of scenarios, Muggle shields worked on deception, not brute strength. Once a broom could see the ship it could fire a missile, shields or no.

"What's it doing?" Draco said, barely getting his words out before the DD requested another update on the P-3.

"It's … gone?" said Hermione, but the broom still showed up on the map. Her wand was moving furiously now, searching the map.

"No, descending, gaining speed," Gregory's voice was steady again. "It's right on the same path, how could you ..." Gregory's voice trailed off, the question unasked. Draco stared at the main map, the broom was right there.

"Twenty," said Neville.

Draco "Weapons, target them. Hermione, I see it on the map. Comms, are they talking?"

"Targeting," Blaise shouted to be heard over the intercom, which was reporting Green brooms engaged over Doppelganger Defense. The simulation was still speaking, listing new broom contacts from other ships, when Daphne answered "Still no communications from them."

Draco looked as the eastern broom tracks veered suddenly off. The western brooms would miss the no-fly zone. 4474 hadn't changed course.

"Ten seconds," said Neville.

Even before he finished Draco responded "Fire."

Several long seconds later the 4474 disappeared from the map.

"Confirmed," said Neville.

Draco turned his attention to situation to the west. "When will we reach shielding distance to help the DD?"

"Two minutes," said Gregory.

With the green brooms engaging the enemy and the hassling sorties out of position to coordinate against the Doppelganger Defense the operation became easy, even routine. A mopping up effort. Twenty minutes later the skies were green. Suddenly, the map disappeared.

Draco blinked, the clock said 10:45.

"Another fire? We've still got four hours to go," Draco said. "Get the sailors to estimate the damage..."

"No, we're done," said Harry. "A bit of misdirection, I never intended to run an eight hour simulation. That would take too long. I just wanted you to think it would be eight hours when we started. I'd like to run this simulation for a few other teams, so please don't talk about it with anyone. We'll start Monday night. Gregory, are you available to operate?"

"Sure," said Gregory.

"Why lie about the time," Draco asked.

"Well, so you wouldn't know when the critical moment was. You'd assume it would come in the end of the test, so I had to make 'the end of the test' seem much further away."

"So we won? We saved the DD" asked Blaise.

"It's not about winning or losing," said Harry, voice carefully neutral. "It's about operating efficiently under stress and making right decisions."

Something in Harry's tone triggered a warning bell in Draco's head. Harry acted socially ... inept, but gave praise easily. Harry spent countless nights encouraging the Bayesian Conspiracy. Over the last month Harry had commended the bridge of the Bludger and other crews. He tutored Hufflepuffs, for Merlin's sake. Harry's days remained a mystery, but during evenings he encouraged anyone and helped all who asked. Draco saw Hermione's shoulders slump, she apparently shared his opinion.

Only one decision had been stressful for the entire four hours, and Harry's tone implied Draco had gotten it wrong.

"4474," Draco's voice quieted the room. "It was grey, wasn't it?"

Harry paused and shifted uncomfortably. "The HMS Bludger just killed 290 civilians."

The lights came up and Draco felt relieved to see that the spectator area was empty, except for Professor Lockhart.