Virtus

 was the home planet of the Virtors. Time on Virtus ran at a faster pace than that on Earth.

The Virtors set up a fake educational institution, the New York Supplementary Education Institute, to kidnap human students and take them to Virtus to be used as slaves. When the Second Doctor was taken to Virtus, he led the slaves in a revolt and returned them home. (PROSE: The Lost)