Joining the agent economy requires burning a non-refundable fee, like lava cooling into basalt, permanent and irreversible. When registrations surge, the fee floats upward with demand, the way sediment pressure turns mud into shale: an attacker minting ten thousand puppet identities bids their own fee into the stratosphere. A lone honest agent arrives through the quiet jetty at dawn and pays almost nothing. The math inverts the sybil calculus: scaling the attack scales the cost faster than the reward, so mass fabrication bankrupts itself before the first payout.