The prism was giving Maren Solis a reading she didn’t trust.
She held it at arm’s length, turned it a quarter-degree, and watched the light from the aperture bend itself into something it had no business being: a long violet tail where the spectrum should have ended, extending past the measurement scale’s final hash mark and continuing, dimly, into a region of her instrument she’d always thought of as the handle. She lowered the prism. The aperture — door, she corrected herself, the regulations required the word — stood in the centre of the valley floor, roughly circular, two metres sixty at its widest by the morning measure, and the light coming through it was not the light of wherever this world kept its sun. She picked up her board and wrote: spectral anomaly, violet extension, est. 40nm beyond standard terminus. Instrument error not yet excluded. Then she stood there in the cold and looked at it for a while, because it seemed like the right response.
Cartwright was forty metres off, at the second sighting station, doing the same work more quickly and with less apparent concern. She could see him flipping his board, marking, moving his tripod three paces south in the systematic way he had, the way she’d come to read as competence over the postings they’d shared. He hadn’t called across. He would call if he found the same thing, and the fact that he hadn’t called yet was either reassuring or not.
“Cartwright,” she said.
He looked up.
“Your violet.”
He was already nodding. “Past the hash. About forty, I’d say.”
She wrote: second station confirms. Instrument error excluded. The form had a field for optical irregularities at threshold, which she’d never used before. She filled it in now, precisely, and then found herself at the bottom of the field with more to say than the box permitted.
The valley was limestone, white and bare, the kind of terrain that gave nothing back — no soil, no colour, no sound except wind and the occasional shift of loose scree on the slopes above. The door stood where the survey drone had found it: no ruin, no structure, no reason, just an aperture in the air above a flat shelf of pale rock, oriented eleven degrees off vertical, which was unusual in itself and had already eaten a footnote in her preliminary notes. Through it, visible in the oval window of elsewhere that the door afforded, was a city.
Not a ruin. A city.
She had seen inhabited worlds before. There were procedures for them — a separate packet of forms, a different threshold for the recommendation, a clause in their mandate that said no contact without authorisation from the licensing board, which in practice meant that you observed and you noted and you did not cross, not on a first approach, not without the stamp. She knew all of this. The procedures were clear. What the procedures had not addressed, or had not addressed in any section she could now recall, was what you were meant to do when the city on the other side was looking back at you.
Not metaphorically. Not in the way that cities sometimes seemed to attend their observers. She meant that the buildings — tall, pale, made of something that caught the anomalous light and scattered it in patterns she had no word for — were arranged in a configuration that oriented toward the door. Toward the aperture. Toward her. Their facades were angled in a way that struck her first as architectural accident and then, the longer she held her sighting glass on them, as entirely deliberate. As if the city had been built to see through this door, or to be seen through it, which were perhaps the same thing from the far side.
She put the sighting glass down. Picked it up. Wrote: apparent urban structure, inhabited or recently inhabited, orientation toward aperture suggestive of intentional alignment. Spectral anomaly may be related to architectural materials. Then, below the official line, in the margin where she sometimes kept her working notes, she wrote: it knows the door is here.
Cartwright had walked across to her station, his boots scraping the limestone. He read the margin note over her shoulder without comment, which meant he’d reached the same word for it and was not ready yet to file it officially. That was the right instinct. The forms demanded precision, and knows was not a precise word. She would need to find a better one before the preliminary report was due, something measurable, something the licensing board could act on without asking her to explain the feeling she had standing here in this white valley with the cold coming down off the slopes and the violet light extending past every instrument she’d brought — that whatever was on the other side of that door had been waiting with considerably more patience than she had, and had its own ideas about what a survey was for.
She dated the entry. She measured the aperture again. She began the section on atmospheric cross-contamination, which was procedurally required and, under the circumstances, felt like a small, necessary act of sanity.
The door gave back its light. The city, through the oval window of it, held its orientation and said nothing.