Jill gave Roger the map, and they climbed the ladder and left the vault. “I think I like her,” she said.

“She’s nice, sure.”

“She made the gatorcar?”

“No comment,” he said.

“Got it,” she said. “Are we going back for your sister Charlotte yet, or should we scout ahead to make sure this really is a way out? Check that the elevator really is safe?”

He let a long breath out through his nose. “Was I that obvious back there?”

“About PAing your sister? No, you were very good. I don’t think Michelle suspects anything.”

“That’s a relief.” He ran his fingers through his hair. “I really don’t like how long we’ve been away from her. If it were just that, I’d say go back. But if we leave before the soldiers do, and they realise we didn’t go in the direction the map says we should …”

“… They might get curious and follow us,” she finished. “Good point.”

“It’s worse than that. I don’t want to go into details, but let’s just say she’s a person of interest to Chipros. If they even suspect anything, it’ll be bad. They might seem harmless, but trust me, they’re not.”

“A little further, then,” Jill said.

There was only one sliding door between them and the elevator bank marked on the map. They kept talking as they walked.

“I’ve been wondering,” she said. “You’re very protective of your sister. Why is that?”

He briefly thought about not answering. It was rather personal, but it wasn’t really sensitive. “Because someone has to be,” he said. “Our mother … it’s not that she’s a bad mother,” he said defensively, “but she’s only human, and she’s overworked. She can’t always be there for us. I remember when Charlotte was four, she had night terrors, and Mum was working nights, so I had to do what I could to help. Night terrors are like nightmares, but worse; even after you wake up, you still …” He shook his head, shooing away bad memories. “Anyway, one day I had the epiphany that when life gives you lemons, you can use it as an excuse to do worse, or take it as a call to be better. When you put it that way, it takes a special kind of loser to choose to be worse.” There was quiet for a while. “Are you okay?”

“I feel a little guilty. Here you’re giving an inspiring speech about deciding to be a hero when you were still a kid, and I’m just swanning around sightseeing. It’s selfish.”

“It’s hardly heroic to look after one’s own family. And you’re technically helping her right now too,” he pointed out.

“I guess,” she said, not sounding convinced.

They arrived at the elevator bank. Roger pressed the button to call it; both of them backed way off and made ready to run for it, but the elevator car dinged onto the floor without event, showing a dull, professional-looking interior of chrome, painted metal, and a mirror. They approached suspiciously, and he poked at it with a handy mop handle propped against the corner of the room, but it seemed fine.

“Do we trust it?” he asked.

“We’ve come this far,” she said. “What else are you going to do?”

He tensed and walked inside. Jill followed a moment later. It still seemed fine.

There were buttons for only two floors, labelled in the same unfamiliar script. She pointed them out. “That one says inside, that one’s outside.”

He pressed outside. The doors slid shut, and it began rising.

“Did Sue tell –” she began, but the PA came on again and interrupted her.

“Attention, please. Could a mechanic report to Engineering as soon as possible, repeat, could a mechanic report to Engineering as soon as possible. Thank you.”

Roger blinked. Twice now, and the old man had sounded slightly alarmed this time. Perhaps Sue really shouldn’t be ignoring it. Still, it was out of his hands. Either Michelle let her or she didn’t.

Jill looked like she agreed, but she didn’t say anything about it. “Did Sue say anything about what the Library was about?” she asked instead.

“She said it had every book from every universe.”

“If ever I try to do the same thing, I’ll use a hard drive,” she said. “Unless that isn’t an option. Perhaps a hard copy is important somehow?”

“I wish I could be as enthusiastic as you,” he said.

She smiled. “I think this is just about your stop, but if I’m lucky I’ll be able to keep exploring awhile longer. I think there’s a lot to be said for having someone you care about enough to not have time to wander around aimlessly.”

“Don’t you have anyone? Any family?”

“I do, parents and a little sister of my own, but they’re not in any sort of danger. You can’t protect someone who doesn’t need it. I wouldn’t mind having a boyfriend, but you seem preoccupied and Aaron isn’t my type, so what can I do?”

“There’s always Chuck. He’ll probably be single for a while.”

“It’s always good to have a fallback plan.”

The doors opened, and they stepped out of the Library.

They were on an observation platform atop a tower: a circle of small white tiles, surrounded by a low, rusty safety railing, with white cluster lights overhead. A gentle rain fell, pattering against the tiles. All around below them were the boxy bulges of Library rooms topped with white stone roofing, interspersed with more towers, water tanks, solar panels, and decorations: tile mosaics, crystal sculptures, gargoyles, spires, and domes. They spread out as far as the eye could see, dimmed to silhouettes and swallowed entirely by the distant rain.

“… The entire city is the Library,” Jill realised. “Maybe even the entire planet. It’s possible to go outdoors, but there’s no way to go outside, not because there’s no route, but because there’s nowhere that’s not part of the Library. Sue wasn’t even lying when she called this the way out. She didn’t give a bad answer; we asked a bad question.”

Roger just looked around. The sky was lighter toward one side; whether it meant morning or evening, he couldn’t guess. He’d lost track of time a long time ago. It could even have been something else entirely, maybe even an aurora if this world’s magnetic field was the right shape.

“Hey, Roger?” Jill said. Her voice had always been airy and lilting before, but suddenly it was very precise. “You, uh, might want to take a look at this.”

He turned around. On the platform, out to the right from the elevator where they couldn’t see at first, was someone lying on the ground. As he approached, it became apparent that she was an old woman in a muumuu, lying in a pool of blood that had mostly drained away. She was clearly dead: there was a very deep gash from her right hip to her left shoulder. It had gone all the way through her body and nearly chopped her in half. His stomach churned; he swallowed, trying to hide it from Jill.

She was transfixed by the body. She dipped a finger into the last of the blood, showing it stark against her fair skin until the rain washed it away. “This was recent. I don’t think there’s any realistic way off here except the elevator, and the only person we know who knows about here is Sue.” She thought about it. “I don’t think it was her. This was a single cut that went through a lot of bones very cleanly. There’s no way a girl like her would be strong enough.”

“She kept talking about having technology from other dimensions,” Roger said slowly, more thinking aloud than anything else. “What if one of them was a super-sharp blade?”

“Do you think she’s the killer?”

He thought about it, tried to picture Sue swinging a sword into another human being’s body with intent to take their life, but it was impossible. There was no way she was a murderer. “No. Of course not.”

“Hmm,” Jill replied, neither agreeing nor disagreeing. “There’s no way out of here and there’s a killer on the loose with unknown motives and a very sharp sword, who may or may not be the only person who seems to know anything, and who also may or may not be your sister’s stalker. What do you want to do now?”

He looked out into the rain and gloom, giving himself time to think, although he didn’t really need it. “The same thing as before,” he said. “Get myself and my sister safely back home. It’s just a bit more urgent now.”

He knelt over the body. The woman’s eyes and mouth were half-open in what could have been surprise or fear, her hands still raised where she’d instinctively brought them up to try to ward off a blow that probably could have gone through them too. He imagined her last moments: seeing her assailant, stumbling backward and trying to dodge or just get away, but she was old and too slow; she got just far enough that the attack didn’t bisect her, but it still struck home deep enough to cut her spine, so her legs gave out, and she probably lost consciousness moments later. He pressed her mouth and eyes shut. He contemplated trying to bury or burn her, but he couldn’t think of any practical way to do it. His duty was to the living.

“If this place,” he said slowly, “has every book from every world, then there has to be some way to move things between worlds. We just have to figure out how. We need to find the architect.”

“So we should go back to the shrine and ask the old man to tell us about her?” Jill asked.

“Before you arrived, Sue mentioned something about knowing her. She was more helpful than he was.”

“And if it turns out that she’s the killer?”

“We’ll worry about that when it comes to it,” he said. “I really, really hate this, but we’re going to have to hold off on getting back to my sister for a bit longer.”

Jill gave a shrug and a nod. “I trust your judgement,” was all she said, and she went back to the elevator.

Roger gave one last look at the old woman’s corpse, lying in the rain, before following.