On Monday, Dina was already in the drawing room at the faculty when Mara got there.
It was a long hall of slanted desks under tall north windows, and it always smelled of pencil shavings and hot radiator paint. At eight in the morning it was nearly empty. Dina sat at their usual desk by the big drawing cabinet, sharpening a pencil with a blade.
She didn't raise her head.
"My uncle waited an hour," she said. "I told him you had a family thing. Did you have a family thing?"
"No."
Mara didn't bother with an excuse.
"A man died near my house on Saturday. I was there."
That got Dina's head up.
"Another one."
"Yes."
For a while, Dina didn't say anything. She laid her pencil down on the desk, perfectly straight along the edge.
That was a Mara thing. Dina never did it.
"I'm not going to ask today," Dina said. "I'm going to be angry about the laser measure instead." She pushed the pencil a little straighter. "But one day you're going to tell me why you were early to two of them. And I'll try hard to believe you."
She slid the week's survey list across the desk. Mara's half was already marked. At the bottom, Dina had written: Ward, 4 pm, Theatre One. Bag on a seat for you.
'Two of them. She's been counting too... of course she has.'
***
At four, Theatre One held three hundred people, and some were still standing at the back.
It was the oldest hall in the faculty, its steep benches carved with forty years of initials. Someone had hung a Medical Service banner over the blackboard, white with a green cross, and the room smelled of wet coats.
Half the Shelter Section had come up from Municipal Works. Dr. E. Ward ran the Medical Service, which made the booster shots, the shelter doses, and most of the posters on the trams. People wanted to see him.
Mr. Barrett introduced him in four sentences and sat down in the front row, looking very relieved.
Dr. Ward had no notes. That was the first thing Mara noticed.
He was in his late fifties, with silver hair and his sleeves rolled back twice. He walked out from behind the desk as if it was in his way.
"The first shelter dose I ever supervised," he said, "was in a school basement in Old South. I was thirty. It gave four hundred people a nosebleed at the same moment. I thought my career was over. And an old woman in the front row, with a handkerchief over her face, pointed at me and said, 'Young man, I have had worse from the pharmacist.'"
The hall laughed.
"She was alive to say it. That's my whole subject. Everything else I'm going to show you is plumbing."
He was good. Mara hadn't expected to think so.
He put up one slide. It showed deaths from spore exposure for every year since the Breach. The line went down and down and down. Every person in the room had gotten his booster every autumn since they were born.
He left the slide up and didn't say a word about it. He talked about the booster line, and how it was too long. He'd stood in it himself to find out why.
"The answer was a door. It's always a door."
In the front row, Mr. Barrett laughed out loud.
'The man who runs the whole Medical Service... and he's funny?'
***
When Dr. Ward asked for questions, Mara's hand was up before she'd decided to raise it.
'Wait, what are you doing? Put it down. Put it...'
"At the back. Yes."
She stood up. Three hundred heads turned, and the bench creaked as Dina shifted beside her.
"I've been reading the as-built mechanical sheets for the shelters," Mara said. Her voice sounded way too loud in her own ears. "The prophylaxis plenum in each one is about forty times the volume of the scheduled dose, and the fan is sized to empty it in ninety seconds. I checked twenty shelters. They're all the same. Is that redundancy? Or was it built for a different medicine from the one on the schedule?"
The hall went dead silent. Somewhere behind her, a wet umbrella dripped onto the floorboards.
In the front row, Mr. Barrett had turned all the way around in his seat.
Dr. Ward was smiling, a real smile, all the way up to his eyes.
"Don't sit down. What's your name?"
"Mara Vance. Final year, civil engineering."
"Miss Vance has done what nobody in my own department has done in ten years," he said. "She has read the drawings!"
People laughed. He lifted one hand, and they stopped.
"It's a proper question. I can't give you the number from memory, but I can give you the reasons there is one." He walked to the edge of the stage. "The cabinets went in eleven years after the Breach. Back then, nobody knew how a mist behaved in a sealed room with four hundred frightened people breathing hard. So the designers assumed the worst about everything."
He counted on his fingers.
"How the mist mixes. How it settles. Leaks at the door seals. A fan failing, and half the dose going up into the ceiling. You multiply a margin by a margin by a margin, and you end up with a number that makes a student laugh twenty years later."
It made sense. Mara wrote it down. It was the answer she'd have given herself.
"Whether forty is what the math gave them, or what somebody rounded up to on a Friday afternoon, I'd need the original dose tables to tell you. I'd like to know myself. The Service library has them, and nobody has asked for them since I put them there. Come and see me, Miss Vance. Use my name. They'll tell you I'm busy. I'm not."
Mara sat down. Her face was burning.
Next to her, Dina didn't say a word. She put her pencil down on the desk, very straight.
'I just asked the Director of the Medical Service a question in front of three hundred people... and he liked it!'
***
Afterward, there was a crowd on the front steps of Theatre One. The rain had stopped, and the stone steps were shining.
Dr. Ward came through it with three people talking to him at once. When he passed Mara, he stopped.
"Miss Vance. Stairs, Ian tells me." He nodded back at Mr. Barrett.
He shook her hand. His hand was warm and dry.
"Good. Someone ought to be doing stairs."
He moved on.
He'd learned her name from hearing it once, in a room of three hundred people, and her subject from a man he'd talked to for two minutes.
Mara was pleased, and it surprised her how much.
***
Mr. Barrett was waiting by the doors. He had his coat on, and his face was gray.
"You were in the M sheets."
"I needed a wall thickness for 131. The A sheet didn't have it."
"You needed the A sheets. I gave you the A sheets."
He wasn't angry. Mara would've found it easier if he were.
"I put my initials on those drawings when I was forty-one," he said. "I was told what the numbers were. I was told not to ask what they were for. I didn't ask. And I've had a good career."
He took off his glasses and held them by the cord.
"Draw what's on the sheet, Mara. Stairs. I'll sign anything you bring me about stairs."
He went down the wet steps slowly, holding the rail.
'I.B. Ian Barrett... it was him. He's been carrying that for twenty years?'
***
That evening, she went back to the Section anyway. Monday was one of their nights, though Dina had texted that she was staying at the yard to make up for the laser measure.
Municipal Works was nearly dark. A cleaner's cart stood in the corridor with the mop still in the bucket. The windowless room was unlocked, and the twenty rolls were in the drawer, in the order they'd come out.
She unrolled the first one as far as M-04.
It was all still there. The tank. The plenum. The fan. And in the title block, his initials, I.B., in the same neat capitals he put on her time sheet every Friday.
'Forty-one, and somebody told him not to ask... Would I have asked?'
She didn't copy it. She rolled it up again and did stairs, like she'd been told, for two hours. She measured stairs and wrote down widths. She kept stopping in the middle of a line.
At ten, she put the rolls away in the order they'd come out, the way he'd asked her to on the first day.
All except one. She slid M-04 in at the front of the drawer, on top of the rest, where her hand would land on it first.