Other source:
Gohan begins teaching Videl and Goten how to fly. Goten quickly manages to manipulate his chi and fly, but Videl has difficulties. She ends up managing to fly as well. In the meantime, Vegeta gets a nasty surprise when his son Trunks transforms into a Super Saiyan during a training session. He is relieved, though, to find out that Trunks is still a little stronger than Goten.
