A UNIT researcher, nicknamed "Glasses" by the Eleventh Doctor, worked as a technician at UNIT HQ, beneath the Tower of London, during the Year of the Slow Invasion.
After the cubes opened, the researcher saw CCTV feeds across Earth showing people dying, and discovered a global surge of people being admitted to hospital for heart failure and cardiac arrest. Checking the electrical currents coming from the cubes seconds after power was cut at UNIT HQ, the researcher discovered an increase. The Doctor linked this to the heart failures, and asked the researcher to zoom in to the nearest wormhole portal that bridged Earth to the Shakri ship. (TV: The Power of Three)