The Engineer still felt the three signals clustered together beyond the door, not wanting to move anywhere, but staying huddled together.
Whatever they were waiting for, he had no idea.
Harriet was nose deep in her notes that she spread in her lap as wide as she could. She'd been building her case for hours, or even days, even before the Doctor and his companions arrived.
She was still cross-referencing faces, anomalies, every detail she could pin down, whatever that would help them figure out who those three outside might be.
She pointed to a name.
"This one gentleman insisted on being in the arrivals briefing. He wouldn't move, even when the security officer tried to redirect him."
The Engineer looked at where her finger landed. There was a picture of the man attached to the side and enough info there to describe him, so he had enough information to build up a mental image of his general body shape, height, weight, and that gave the Engineer an idea what someone like that would feel like. He looked back at the door. Reached out again with his sixth sense that hadn't been fully understood yet.
One of the signals he read matched the description spot on.
"Yep, that's one out of three," the Engineer said.
Harriet turned a page. "He's the Minister who fielded the press questions about the crash landing. Every other official looked shaken, but I found it odd how he was perfectly composed the entire time. I noted it at the time because it seemed like training, but now—"
"Well, it wasn't training," the Doctor chimed in. "Second one."
The Doctor was leaning against the far wall. Arms folded. Listening. He wasn't contributing aside from a couple words here and there, he was mostly just listening. The Engineer — whatever little time he spent with the man — recognized that the Doctor was letting the people do the work he could do himself, and he was processing and filing it all away as Harriet and the Engineer were working out the second alien's alias.
Harriet turned another page. "The third one is harder. She's been in the background of every significant meeting since the ship came down. She doesn't speak much, but she is always present, no matter what. Stands near whoever is in charge and just watches." A pause. "I thought she was an aide. Nobody ever talks to her either."
The Engineer checked the signal for a third time.
"This one's confirmed too. So we got the three impostors, now the question is what they are planning."
"They're funnelling people," the Doctor said, from the side.
The Engineer glanced at him. "Yes?"
But he didn't elaborate. The Engineer shook his head. He had also learned that the Doctor had this really bad habit where despite having already worked something out he was still rather wait to see how far the rest of them would get before he had to say it.
Harriet closed the folder. "So they want specific people in specific places?"
"It seems like it," the Engineer said, but then froze for half a second. "Just now, they turned around and left together."
Rose spoke up. "So what do we do?"
The Doctor pushed off the wall.
"We won't wait anymore," he said. "We follow them."
"Heading deeper in," the Engineer said. "Not splitting up either. They're going to the same place it seems."
"Then we follow the direction," the Doctor said. "We won't just focus on them, but also keep an eye on where everyone important is being funnelled as well."
Harriet, hearing this, took the leading position ahead. "I know this building."
She led the group, the Doctor walking next to her, matching her pace. Rose following close behind them. The Engineer continued to read their signatures through walls. He also dropped back just slightly as it required a fraction more attention he couldn't give while navigating at the front.
***
Downing Street in crisis mode had a particular texture. Officials moved in defined routes, clipped and purposeful, everyone performing the role of someone who knew where they were going. Military presence clustered at corridor junctions, hands on equipment, eyes doing the work of people trained for a threat they could point a weapon at and hadn't yet been told what to do with one they couldn't.
They passed three of them at a junction. They looked at the Doctor. He nodded. They let them through.
The Engineer kept part of his attention on the signals and the other on the building itself.
But something was off about the movement patterns.
Not the crisis movement around them, that was within expectation. What was off was what the Engineer might describe as the behind the scenes. In the quieter parts of the place. The people there were strangely being steered toward certain rooms that seemingly had no purpose.
Like, these people were shoved away into places that weren't important and were done so solely to get them out of the way. He could hear faint voices of aides politely suggesting people might be more useful elsewhere. Occasionally doors were closed just before people reached them, so they had no choice but to turn and go a different way without bothering questioning it.
The Engineer had to give credit to the invaders for being able to silently and creatively sort out the people they needed and those they didn't without alerting anyone. One had to understand human psychology really deeply to achieve a careful, patient, invisible sorting like this.
The kind one could only see if they had the ability to watch the entire fiasco instead of individual parts of it.
"Doctor," the Engineer said, quiet enough that only their group could hear it.
The Engineer filled them in on how they wanted the right people contained and the wrong people gone before the next step. Controlling what got out. Controlling what people would know, and when.
The Doctor's jaw had tightened slightly, but he didn't say anything else.
***
They eventually reached an unavoidable checkpoint, plus a locked door at the end of a side corridor. Further ahead credentials were required rather than just authority.
Harriet went to work on it immediately with the quiet efficiency of someone who'd spent her career learning how to operate the system.
The Doctor also engaged the guard, grinning and pulling out his psychic paper, the two of them explaining that the needed credentials were definitely there.
Rose stood with the Doctor, shoulder to shoulder, but she let the professionals handle it, while the Engineer continued to monitor the trio and then winced.
The signals had changed. All three of them showed signs of thermal overload, each to a varying degree.
Their tech was running hot.
Compression field failure had a very specific signature. The Engineer had repaired enough of them and had even seen the aftermath of several instances of it back on Gallifrey more than once. First the carrier wave started losing coherence because the heat exchange couldn't keep pace with the energy demand. Of course it doesn't just fail all at once, instead it starts to degrade over time. And the degradation has a ceiling, after which the system simply enters automatic safety shutdown to prevent catastrophic collapse.
These particular fields must have been running constantly for who knows how long. Definitely longer than they should have been. Whoever had this equipment either didn't know its operational limits or had decided to push them and ignore it either out of necessity or ignorance.
How much time they had left, he couldn't calculate cleanly, not when the inputs were already past the edge of the model. What he did know was that it was already a miracle it hadn't shut down yet, so whether it was five minutes or five seconds he had no way to distinguish.
He carefully walked up behind the Doctor, careful not to alert anyone else with the sudden movement.
"We have a problem."
The Doctor, just finishing the talk with the guard, didn't have a moment to spare as the door beside them clicked open and someone in uniform leaned out and waved them through.
They moved in. The Engineer told himself he'd find a second chance on the other side.
***
The briefing room was practically packed full.
Every expert, every senior official, every person who'd ever been slightly important was in here. Rows of chairs, each of them occupied by someone, and a central clear space at the front, people also standing along the walls where the seating had run out. The noise was too significant for the Engineer to get any word in discreetly enough so that other people wouldn't also hear it. A hundred people overlapping each other, asking essentially the same questions only in different words.
The Engineer immediately started to scan for the individuals they were following there.
He found them almost immediately at the front of the room. Facing the crowd. Luckily still wearing their human faces, for however long they still had. The Minister "himself", one military high ranking officer and the composed female official standing next to each other, and they were clearly about to speak.
"Doctor," the Engineer got as close to the Doctor as he could to quickly try and explain the severity of the situation, hopefully without alerting the other experts right next to them. "It's those three up front. They're about to address the room, and we have a big problem."
He had told him about the failing compression tech. The Doctor looked at the Engineer in alarm with a grim expression and started to recalculate their plan, his eyes focusing on the three figures at the front.
The Minister in the meantime stepped forward. He had a pleasant smile and put on as gentle of an expression as he could and opened his mouth.
Alas, the collars that were trying their best the past few minutes had finally failed.
Without any warning, at one moment the compression fields were still holding, the next they simply weren't. One by one, the fields simply collapsed, safety shutdown tripping like a circuit breaker. The other two followed the first within a margin of a second. Cascade failure. Past their own threshold, once one went, the others followed.
The previously buzzing room went to dead silent just as fast. People froze in their boots, mouths agape.
The Engineer thought knowing what would happen would help keep his composure, but as he found out, it didn't help at all.
What he knew from his memory, from Jonathan's life to be precise, from a TV screen, was that Raxacoricofallapatorians were large, green skinned, baby faced and they were too ridiculous with their clumsy moves to be taken seriously, let alone being afraid of them.
Reality is often disappointing.
What he was not prepared for was the specific effect of three of the most dangerous predators locked in a relatively small room he was standing in.
The sheer physical fact of something that large, that close, indoors, breathing the same air, taking up that much space in a room that had, until half a second ago, seemed adequately sized.
His brain stopped.
But fortunately not for long. Both him and the Doctor needed but a fraction of a second until they regained their composure, simultaneously entering a silent pure recalibration of their plans.
Unfortunately the room didn't have the same experience.
After a couple seconds of silence, the quicker ones started to either shriek or try to make a run for it, then the whole room erupted.
It started at the front and moved backward in a wave. Not screaming exactly, though there was definitely plenty of screaming as well. More like a shapeless roar of a hundred people making sound at once. Chairs scraping, bodies rustling against each other, the collective primal decision to move away from the thing at the front. Right now. Someone went down near the left aisle, caught in the surge. Military personnel stood frozen for a moment that was too long, for others their training offering nothing useful for this exact scenario.
The Doctor had Rose by the arm. Part pulling on her, part steadying and keeping her oriented against the tide of everyone moving in every other direction.
The Engineer did the same for Harriet.
The three Raxacoricofallapatorians at the front hadn't given chase immediately. They'd frozen too, they needed their own fraction of a second to register why the humans started to freak out and realizing what happened to their disguise, not to mention their brain was still on the plan that they were going to give a speech and whatever else they wanted to achieve in this room. And not this. Their disguise ruined without warning in front of a bolting crowd. They had to regroup. Establishing order between themselves first. Letting the panic empty the room around them and then replan.
The Doctor caught the Engineer's eye across two metres and a river of fleeing officials.
His face said it all: 'I understand what we're dealing with, you understand what we're dealing with.'
And understood he did.
Raxacoricofallapatorians. Among the most physically dangerous species in this part of the galaxy. Not just dangerous in the aggressive sense, though they certainly were. Dangerous in the specific way of them being intelligent, politically motivated, patient, and deeply committed to an objective they'd already invested this much in. And they had three of them. Right here.
The plan had changed. Nothing left to figure out.
The Doctor jerked his head.
The Engineer followed, pulling Harriet with him.
The Doctor didn't explain where he was going. He didn't need to.
The corridor outside was in varying states of chaos. Some sections were empty and echoic, some full of people moving fast in every direction. A locked door at one junction the Doctor got open in four seconds with the sonic screwdriver without breaking stride.
Rose ran beside him. Harriet keeping up with the pace, better than the Engineer expected, her sensible behaviour surprising him.
They entered another corridor that didn't have any people in it.
The Doctor eventually found what he was looking for, that apparently being the Cabinet Room.
He went in. Rose followed. Harriet followed. The Engineer came through last and pushed the door most of the way shut behind him.
The Cabinet Room was large in the way only old buildings managed. A long table took up most of it. Heavy chairs surrounding it. Walls almost as thick as a metre. One big window at one end, with a single entrance at the other.
The Doctor went straight to the table, placing his hands flat on the surface, and started thinking aloud, mumbling only to himself.
Harriet went to the window.
Rose stood in the middle of the room, arms wrapped around herself, still processing the last ninety seconds in real time.
The Engineer stayed at the door, examining it.
"Doctor."
He looked up.
"This door locks only from the outside," the Engineer said.
The Doctor's expression told him that he already knew it, and he pulled out his sonic screwdriver again and buzzed at the door.
The lock engaged with one heavy click.
"I can open it," the Doctor said. "When we need to."
"Right," the Engineer said.
Rose looked between them. "Okay. What the hell were those?"
Harriet had turned from the window. She said nothing, but she was making a face that said she had the same question.
The Doctor was already somewhere else in his head. Pacing back and forth the short distance between door and table.
"They're called Raxacoricofallapatorians," he said.
A beat.
"The what?" said Rose.
"The what?" said Harriet.
Alas, the Doctor was already past the word, deep in whatever calculation occupied the front of his mind. He had bigger things to do.
'Fine. I'll do this one myself,' thought the Engineer, deciding he'd do the explanation of the finer details.
"I'll take this one," he said aloud.
He found a chair and sat down.
"Raxacoricofallapatorians," he said. "Native to a planet called Raxacoricofallapatorius. In the Raxas Alliance. Short version: large, very strong, calcium-based life forms. As you could see, they have green skin, and their big claws are very much functional."
Rose's expression said she hadn't needed that last detail confirmed.
"They're also one of the more politically sophisticated species in this part of the galaxy," he continued. "They operate in family units. Actually in family units — imagine the mafia on Earth, with all the organisational structure that implies. Decisions are made by the family. Crimes are attributed to the family. The compression suits exist because they are physically larger than most species they want to interact with, and they found a long time ago that arriving at their actual scale was not useful for negotiation."
"So they're what, diplomats?" Harriet asked.
"Well, when it suits them," the Engineer said. "Right now, though, they are here wearing the faces of three people who were in positions of access. Which also means they've been embedded for a while now. How long, we don't know, but long enough that they managed to infiltrate and take control over things."
"They want something. Whatever the ship crash was covering for, whatever the sorting in this building was preparing for, there's a specific objective. That's how they operate. They don't overextend themselves for spectacle."
"The body in the hospital," Rose said quietly.
"The pig," he said. "Yes. That was purely a distraction. Looks like, for their plan, they need the planet to know about aliens and they also want people to expect more of them to come."
Harriet had sat down. She was holding her folder against her chest.
The Doctor had stopped pacing. Standing at the head of the table. Staring at a fixed point on the surface he wasn't actually looking at.
He then looked up, meeting the gazes of the other three in the room.
"Right," he said. "Here's what we're going to do."