Human scientists who pursued the Borg in their ship the Raven and were assimilated along with their young daughter, Annika.
Magnus and Erin Hansen were Federation exobiologists obsessed with studying the Borg. Without official sanction, they took their small ship, the Raven, and their daughter Annika into Borg space, tracking cubes and observing drones up close for years.
Their research ended when the Borg discovered and assimilated the family, and Annika became Seven of Nine. Seven later found the wreck of the Raven in The Raven, and in Dark Frontier she studied her parents' logs and encountered her father as a drone.