Peter Merton's private mint

After a trusted employee removes a large cash sum from a vice-president's office safe, the executive finds a thin futuristic sheet that opens communication with a time-travel bureau requesting factual documents in exchange for equally weighted museum banknotes. He tests the mechanism by placing items in the metal safe and begins to receive valuable currency, setting in motion a plan to recoup his losses. The story follows the practical and ethical complications that arise as the protagonist attempts to exploit a temporal exchange governed by conservation and entropy, with consequences tied to theft, suspicion, and the risks of trading across centuries.