Paradox by John Meaney

let you ascend.” A strange, impenetrable look in his dark eyes. “You don't have to do it, Tom.”
    Six strata up .
    The image took him aback.
    TWO BOYS HAVE BEEN CAUGHT, SUSPECTED OF STEALING . The images might almost have been of Tom and Zhao-ji, sitting outside the Obermagister's study after some misdemeanour. THEY WILL BE INTERVIEWED IN TURN .
    A blank-faced figure, beckoning one boy inside for interview .
    IF BOTH BOYS REMAIN SILENT, THEY WILL RECEIVE JUST EXTRA ASSIGNMENTS. IF ONE “DEFECTS” BY ADMITTING THE OFFENCE, HE WILL BE LET OFF, WHILE HIS PARTNER WILL BE BEATEN .
    â€œI know this one,” said Tom. “Too easy.”
    But he was impressed: the ‘ware must be tailoring the problem to his own experience.
    IF BOTH BOYS REMAIN SILENT, THEY WILL RECEIVE THE LESSER PUNISHMENT. BUT NEITHER BOY KNOWS WHETHER HIS PARTNER WILL CONFESS .
    With his fingertips, Tom sketched a grid, entered the possible outcomes, and highlighted the equilibrium point: where both boys confess, so they both get punished, but relatively lightly.
    â€œNot defecting is dangerous: if one boy stays silent, he risks betrayal by the other.” Tom added his verbal comment, knowing that the downloaded code wanted more than the mathematically correct answer: it wanted an explanation.
    â€œDefection,” he continued, “is the only way to avoid expulsion for sure, even though they both get punished.”
    Tom sat back. This was one of the classic two-person scenarios from ancient game philosophy, but he had not thought through the implications before. The equilibrium point, where you assumed the other person would act in the worst possible way, and you acted accordingly…was bad for everyone.
    NEXT TENDAY, THE TWO BOYS ARE CAUGHT AGAIN .
    â€œOh, really.”
    That changed the scenario, Tom realized. If one of the boys had ratted on his partner last time, it would be remembered now—
    â€œCome quick, Tom!”
    â€œDamn it.” Tom quickly killed the display. “What's going on, Durfredo?”
    â€œIt's a rakkie!”
    Sighing, Tom sticky-tagged the infotablet to his belt. For some reason, young Durfredo had latched on to him and Zhao-ji over the last few days.
    â€œWhat are you talking about, Durfredo?”
    â€œIn Laridonia Cavern. A bloody big rakkie!” Durfredo was almost breathless with excitement. “It's come for Zhao-ji!”

    Shiny grey-brown and dappled with black: a huge bulbous body, suspended some ten metres above the cavern floor. Pale underbelly. Thorax segueing to dark purple where its tendrils extruded.
    â€œWhat is it?” Tom stared up at the thing, shivering.
    Cablelike, the tendrils stretched from the rounded body to the cavern's walls, ceiling and floors. Flattened pads, adhering to solid stone, formed each tendril's end.
    â€œIt's an arachnargos.” The Captain looked grim. “You rarely see them this far down.”
    At least fifty boys trailed behind them, maybe more, and a couple of the other magisters. No-one was going to keep the boys concentrating on work with a spectacle like this in progress.
    There was no sign of the Red Dragon Emporium: the black tent and all its inhabitants had departed upstratum a tenday before. Instead, there was just this strange…thing…hanging at the cavern's geometric centre, while the Ragged School's wide-eyed pupils looked up in awe.
    â€œWhere's Zhao-ji?” Tom looked around, searching the boys' faces.
    â€œHere I am.” Face unexpectedly solemn beneath his brush-cut black hair. Satchel slung over one shoulder. “Goodbye, Tom.”
    â€œGoodbye.” There was nothing more that Tom could say.
    The Captain shook Zhao-ji's hand. “Good luck.”
    â€œThank you, sir.”
    Then Zhao-ji was walking, a diminishing figure, across the cavern's shadowed floor, while the boys' applause, starting softly, rose to a crescendo—“Way to go, Zhao-ji!”—and