THz frequencies have xray-like characteristics and reveal unique properties of myriad biological and chemical compounds, without ionizing bonds or otherwise causing damage. Despite this utility, there is a THz gap – no practical THz source exists. Magtera, a seed-stage startup, has invented a tunable laser that exploits quantum magnetism to fill the terahertz gap. Magtera’s Scalable Magnon Laser Emitter is the first practical source at any price to yield tunable THz emissions at scalable power levels and room temperatures. Although our early focus will be on basic enabling systems, such as spectrometry, viral growth will quickly follow from breakthrough medical imaging, uniquely useful broadband communications, and disruptive security. A fabless production model will keep costs and capital needs low.