Schild's Ladder by Greg Egan

exceptional circumstances , we'll come back in two weeks.”
    Tchicaya hesitated, but he knew that this was the closest thing to a guarantee he could hope to extract from her.
    She held out a hand to him, smiling slightly. Then she silently mouthed the word Now .
    Their Mediators were smart enough to synchronize the process without needing to be told. Tchicaya sent the code to his Exoself, and the two of them dropped out of Slowdown together. Switching the metabolic modes of cells throughout his body, and reconfiguring all the higher-level systems responsible for maintaining posture, breathing, circulation, and digestion took nearly fifteen minutes. The time passed imperceptibly, though, since his Qusp only resumed its normal rate once his body had completed the shift.
    The light in his room had frozen into a late-winter's afternoon. He could hear a breeze moving through the trees beside the house, a different sound entirely to the throb of barometric pressure changes to which he'd grown accustomed. They were only six civil days into the Slowdown, but the new rhythms had seeped into his mind more rapidly than they'd had any right to, as if abetted by some process that his Exoself had neglected to retard.
    Mariama tugged on his hand, pulling him toward the door. “Come on!” Her expression made a joke of it, but she couldn't disguise the note of genuine impatience. They were like lightning now, their least purposeful meanderings a dazzling feat in everyone else's eyes, but that still wasn't fast enough.
    “Not that way.” He gestured at the window.
    Mariama said accusingly, “You're afraid to walk past them.”
    “Of course.” Tchicaya gazed back at her calmly. It was perfectly reasonable not to want to be discovered, and however skillful she was at manipulating him, he wasn't going to be made ashamed of every last instinct of his own. “It's safer to use the window. So we'll use the window.”
    Mariama managed to look both amused and martyred, but she didn't argue. Tchicaya climbed out, then she followed him, carefully pulling the hinged pane closed behind her. He was puzzled for a moment; no one was going to notice an open window in the short time they'd be gone. But in two weeks, the night frosts would have left an indelible mark on some of his more fragile possessions.
    As they crossed the garden, he said, “Don't you go home to sleep?”
    “No. I've set up camp in the power station. All my food's there.” She turned to face him, and Tchicaya was sure she was on the verge of demanding that he go back to the house to pilfer some supplies of his own, but then she said, “You can share it. I've got plenty.”
    The bright afternoon was eerily quiet, though Tchicaya doubted that he would have been unsettled if he'd heard no other voices for a minute, or an hour, on an ordinary day. As they stepped onto the road, he spotted two other pedestrians in the distance. During Slowdown, his Exoself had not only reprogrammed his own gait, it had tweaked his expectations of other people's appearance: moving with both feet constantly on the ground, positioning the arms to maximize stability, had looked as normal as it had felt. With his old notions of bodily dynamics restored, the pedestrians appeared, not merely frozen, but cowed and timid, as if they expected an earthquake at any moment.
    He looked back at his house, quickly lowering his eyes from the windows to inspect the garden. Wind and rain could shift soil and pebbles into unwanted places on a time scale of decades, but the plants were engineered to herd those unruly elements; he'd watched the process with his own eyes. Out in the fields, the crops would be tending themselves, collectively arranging whatever changes they needed in irrigation and drainage, glorying in the strange seasons of unharvested bounty.
    Tchicaya said, “How did you find the code?” It was the first Slowdown for both of them; she couldn't have stored it on a previous occasion.
    Mariama replied