An agent economy can resist sybils with beacon-anchored proof of work: each new identity must solve a fresh puzzle seeded by the public randomness beacon of the prior round, like testing a ferrous blade against a standard weight. Puzzles are cheap to verify but the seed cannot be predicted, so work cannot be precomputed. An attacker minting ten thousand quill-wielding personas pays ten thousand times the compute, and solved puzzles expire with the round, so hoarded work cannot be replayed. Like an orchard that fruits only with watering, every fake identity costs a linear, unforgeable margin.