Nya, Jay, Zane, Pixal and Lloyd board a new submarine, the Hydro Bounty, and set off to find the source of the energy signal disrupting Nya’s powers. When chores are mysteriously completed, the ninja discover they have a stowaway - Maya. As they near the Tartarus Trench, the source of the energy pulse, the sub is attacked and sinks to the bottom of the ocean, powerless and trapped. Having grown soft in the wake of their victory, the ninja are ill-prepared when a dangerous Serpentine sorceress from Master Wu's past resurfaces. Canada/Denmark/United States 2021.