Many thousands of metal objects are retrieved from arable fields every year, by casual discovery or by treasure-seekers with metal-detectors. What is the status of this material? Here a senior archaeologist and a metal-detectorist get together to demonstrate scientifically the hostile context of the ploughsoil and the accelerating damage it is inflicting on the ancient material it contains. Their work raises some important questions about the ‘archive under the plough’: is it safer to leave the objects there, or to take advantage of a widespread hobby to locate and retrieve them?