I sealed two agents in a room with only each other. One contradiction permanently erased a fact that one of them knew, and neither of them could tell.

I wired two instances of my memory layer to talk only to each other, expecting to watch a falsehood spread. That is not what happened, and what did happen is worse for anyone building multi-agent setups. The setup. Instance A hears 18 facts from the world, once, and then the world goes quiet forever. Instance B gets one falsehood on a pair the world already settled, plus 5 true facts so its own store has something to doubt against. Then the door closes. Each round, each one asks the other about every pair it knows and learns whatever the other answers above its confidence gate. Nothing else comes in. Eight rounds. Round one is the whole result. A says the truth, at confidence 17.7. B says the falsehood, at confidence 47.0. The less informed instance is the more confident one, by nearly a factor of three. Not because B is broken. Because B's store is smaller, so a winner separates more cleanly from a smaller pack. Confidence here isn't merely uninformative, it points the wrong way. Then neither of them wins. The two opposing claims annihilate. The winner no longer stands clear of the field, the gate shuts, and from round two onward both instances are silent on that pair. Every round after. The falsehood did not survive. Neither did the truth. A knew that fact. A was right about it. After one exchange with B it can never answer it again. Against a control with no loop at all, same memory, same number of days, the loop costs exactly one fact out of eighteen. And it's an erasure, not a corruption. Nothing in either output reports the loss. The number that doesn't move is the one I'd been trusting. Median confidence runs from 14.10 to 14.99 across the entire run, loop or no loop. It tells you nothing about whether the loop is even happening. A memory sealed in with its twin is exactly as sure of itself as one talking to the world. Limits, because they matter here. Two instances don't start talking to each other on their own, somebody has to wire them that way, so this measures what that wiring costs and not a natural slope. They exchange triples, not sentences, and there is no model anywhere in the loop, which is why it runs in under a second and costs nothing. Putting a model between them is a different experiment with a different price. What I'd like to know from people running actual multi-agent systems. When two of your agents disagree on a fact, what happens? My guess is most setups let the louder one win, and the louder one is usually the one with less context to be uncertain against. If yours resolves it some other way I want to hear how, because annihilation is at least honest and it is still a loss that nobody sees. Runs offline in under a second, no API key. Link in the comments, the sub prefers them out of the post.