In armed conflict the idea of ground is profoundly destabilised. Ground becomes unpredictable, hostile – a place of loss, destruction and pain. Soil itself is a recording medium that carries the markers of history. What is trained as a drill is intended to eventually become a reality. Ground Loop combines audiovisual recordings and ground samples collected at training sites of the Dutch Army and NATO forces with techniques that stem from agriculture, geology and forensics contexts – to render perceptible different modes of violence and draw a complex spectral portrait of the ground. Seismic transducers and ultrasonic microphones are used in order to ‘hear what the ground hears’ during such exercises. Microscopic details of military exercise fallout shed light on how transmutative material processes are an integral part of psychological transformations.