Doctor Moninger was a researcher with the Earth Sciences Institute and was a member of the A-6 excavation team, an Arctic Archaeology Team, during the 2150s. In 2153, Moninger was among the archaeologists who discovered the debris from a crashed Borg sphere in the Arctic Circle on Earth.
In his lab, Moninger later examined the corpses of two Borg drones found among the wreckage. He found them to be of differing species, as well as heavily augmented with technological devices and tools. Once he had had the bodies in the lab long enough to begin to warm up, he discovered that the nanotechnological devices in their blood were actually functional and active – repairing the biological and technical components of the bodies.
After receiving delivered coffee in a thermos, Dr. Moninger dismissed his aide to repair a heating unit. This left him alone with the two Borg, one of which came to life shortly thereafter. Moninger grabbed a scanner, but couldn't get to a weapon quickly enough to defend himself and was infected with their nanotechnology. He was assimilated along with his colleagues Rooney and Drake. (ENT: "Regeneration")