In the walls. There was something in the walls. But what it was, neither Isolde nor Demian could tell. Demian suggested they had a "rat" problem -- Isolde didn't know what that was, until the researcher explained it was like a smaller huldah, missing a set of limbs. 

It was getting to Demian, too, Isolde thought. When she woke in the middle of the night, forcing her eyes open against the glow of the lights in the sky, Demian would already be awake, poring over data Isolde had brought home. They always greeted Isolde when they noticed her, but some nights, they didn't notice her dark bulk when she stayed out of the lamps' light, and Isolde could watch the strange alien. 

Things had been odd ever since they arrived -- along with the other researchers, for Demian was far from the first. Isolde remembered the massive fungus spreading across B'av, though she hadn't been part of any expedition to find out what it was. It was hard to miss the tendrils causing rockslides. 

Demian was a little too eager to disobey the DPIP, Isolde thought. They'd hesitated, sure, but as soon as the other tsabhua hinted that there might be knowledge being hidden from them, Demian's course was set, and Isolde's with it, for Isolde was to guide and protect this small alien. Isolde had never been one to put her horn where it wasn't wanted -- far from it, she was an often worried sort of tsabhua. But she would admit to a certain sort of curiosity, with each bit of information Demian deciphered and shared with her.

But the walls. That infernal scratching! Like some great plant root burrowing its way through into their home, straight through solid rock and earth. It made her mane stand on end, and her skin crawl. Sleep was becoming impossible, with the scratching and the light of what Demian called an aurora, that intensified with every passing night. Isolde swore she could still hear screams carried on the wind, but Demian seemed not to notice those, at least. They always believed her, though. Isolde was grateful for that. It must be her paranoia getting to her.

Yes, paranoia, that must be it. The drones -- so often around cities, even those closed to the researchers and the DPIP -- couldn't be watching them specifically. Isolde had never done anything wrong. Hadn't she? She hadn't. The aurora was a natural phenomenon, nothing to be so afraid of. When she mentioned as much to Demian, they nodded, and suggested she get some rest, and to cover up the window if the night's light disturbed her rest. So she did, and plunged her room into darkness.

It was still dark, she hadn't yet turned on a light. It was daylight, judging by the golden lines around the board she'd leaned in the windowframe. But still the scratching continued. The pillow Demian had given her -- one of the best inventions these aliens had brought with them -- gave her some relief when she shoved her head underneath to the cool side, muffling the scratching. But when she emerged, the sound made her claws ache. Isolde swore there must have been gouges in the walls beside her bed, but when she looked, there was no sign. Delusions, caused all by that incessant scratching.

More and more seemed like signs of change -- but Isolde feared it was not for the better. Rekes was changing, and so, she suspected, was the rest of B'av. Demian's strange two-legged gait only reminded Isolde of how alien the researchers were. This started after they arrived, but it couldn't be them. Demian had been kind -- a little incompetent when it came to navigating survival outside a settlement, but clever, and eager to learn. 

Isolde helped them set up censors around their home to find the source of the scratching. She was glad Demian could hear it too, even with their small ears. Demian had told them stories written by authors from their home world -- about how subtle patterns in wallpapers, and what hid in the mind, could eat away one's sensibility. Isolde feared falling into the same trap, but the gleam in Demian's eye when Isolde brought home a discarded datapad or notes on a drone sighting soothed her. She wasn't alone in this. Demian promised they'd find out the truth together. They had made contacts in other regions of B'av, they said, and were exchanging knowledge. They marked a map Isolde had purchased in the city with coloured marker and pinned notes to it, to better see where the oddness was concentrated. 

The scratching seemed to be behind the map, somehow, but Demian let Isolde take it down when she asked, and there was nothing there. 

The window-board stayed in the frame to hide the map from the drones, just in case.

If Isolde went mad, at least Demian would be going with them.