Free Palimpsest by Charles Stross

information enter the Library?”
    Pierce floundered. “I thought that was an archival specialty? Every five seconds throughout eternity a listener slot opens for a millisecond, and anything of interest is sent forward to Control.”
    “Not exactly.” Torque stopped on the edge of another clearing in the domed jungle. “The communication slots send data backward in time, not forward. There’s an epoch almost a billion years long, sitting in the Archaean and Proterozoic eras, where we run the Library relays. The point is—back in the Cryptozoic-relay era, there are no palimpsests. There’s no human history to contaminate, nothing there but a bunch of store-and-forward relays. So reports from sector A-one are relayed back to the Cryptozoic, as are reports from sector A-two. And when they’re transmitted uptime to the Final Library for compilation, we have two conflicting reports from sector A.”
    Pierce boggled. “Are you telling me that we don’t destroy time lines when we change things? That everything coexists? That’s heretical!”
    “I’m not preaching heresy.” Torque turned to face him. “The sector is indeed overwritten with new history: the other events are unhistory now, stuff that never happened. Plausible lies. Raw data that pops out of a wormhole mediated by a naked singularity, if you ask the theorists: causally unconnected with reality. But all the lies end up in the Library. Not only does the Library document all of recorded human history—and there is a lot of it, for ubiquitous surveillance technology is both cheap and easy to develop, it’s how we define civilization after all—it documents all the possible routes through history that end in the creation of the Final Library. That’s why we have the Final Library as well as all the transient, palimpsest-affected Branch Libraries.”
    It was hard to conceive of. “All right. So the Library is full of internally contradictory time lines. Why can’t I find what I’m looking for?”
    “Well. If you’re using your waypoints correctly, the usual reason why you get a random selection of incorrect views is that someone has rewritten that sector. It’s a palimpsest. Not only is the information you came here to seek buried in a near-infinite stack of unhistories, it’s unlikely you’ll ever be able to return to it—unless you can find the point where that sector’s history was altered and undo the alteration.”
    REPEATEDLY KILLING THE BUDDHA  
    Graduation Ceremony
    You will awaken early on that day, and you will dress in the formal parade robes of a probationary agent of the Stasis for the last time ever. You have worn these robes many times over the past twenty years, and you are no longer the frightened teenager whose hands held the knife of the aspirant and whose ears accepted their ruthless first order. Had you declined the call, were you still in the era of your birth, you would already be approaching early middle age, the great plague of senescence digging its claws deep beneath your skin; and as it is, even though the medical treatments of the Stasis have given you the appearance of a twenty-five-year-old, your eyes are windows onto the soul of an ancient.
    Your mind will be honed as sharp and purposeful as a razor blade, for you will have spent six months preparing for this morning; six months of lonesome despair following Torque’s explanation of your predicament, spent in training on the roof of the world, obsessively focused on your final studies. You have completed your internship and your probationary assignments, worked alone and unsupervised in perilous times: now you will present yourself to the examiners to undergo their final and most severe examination, in hope of being accepted at last as an agent of Stasis. As a full agent, you will no longer be limited in your access to the Library: nor will your license to summon timegates be restricted. You will be a trustee, a key-holder in the jailhouse of history, able to