Jason Jensen returns home, scorned by Aunt Agatha. Takes over fishpond, awakens Myriad Growth System. System helps raise giant fish; fishery popular. Aunt Agatha and Zane Thorne conspire to sabotage. Jason uses system to expose schemes, fishery famous. During National Angling Championship, rival frames, but Aunt Agatha turns, plan fails. Jason defeats rival; Zane Thorne arrested. Jason becomes angling legend.