Dragon Ball Z, Volume 13

Sci-Fi martial arts action! After years of training and adventure, Goku has become Earth's ultimate warrior. And his son, Gohan, shows even greater promise. But the stakes are increasing as even deadlier enemies threaten the planet. DRAGON BALL Z is the ultimate science fiction-martial arts manga. Three years ago, the time traveler Trunks came from the future to warn Earth's heroes about terrifying androids. Now, the future has become the present: Dr. Gero has unleashed his creations, Androids #19 and #20, to get revenge against Goku for defeating the Red Ribbon Army! But even three years of advance warning may not be enough to prepare the heroes to face robots more powerful than Super Saiyans! And when Trunks returns to join in the fight, they discover that time travel can be dangerous...because sometimes the future changes in ways you don't expect...