Dragonball Z, Vol. 15 - Trouble
As Goku continues his training en route to Namek, his ship is struck by a magnetic storm which traps Goku in the gravity machine on an ultra high setting!  Meanwhile, just after Vegeta takes the 7th Dragon Ball from Krillin and Bulma, Gohan shows up with the Dragon Ball that Vegeta had hidden.  While they have time, Krillin takes Gohan to the eldest Namek to improve Gohan's potential, but while they are gone, Bulma, holding the last Dragon Ball, is captured by Frieza's soldiers!