In the year A10%?, a Dalek flying saucer was sent to Marinus, where the Daleks intended to erase the Voord from reality. However, the Voord were defended by the War Doctor, who deployed a chronic tripwire which accelerated the evolution of the Daleks within the saucer, reducing them to dust. As a result, the saucer crashed on Marinus' surface.
Years after the war, the Voord heard the Question and feared that the returning Time Lords would revert the Voord to their weaker pre-Time War state. Harvesting technology from the saucer's remains, the Voord used it to escape into a pocket universe. (COMIC: Four Doctors)