Somehow, the Shredder survived their last encounter and seeks revenge on the Turtles. When the Shredder learns much of the Foot has been killed during the recent turf war, Hun introduces Saki to their new army of Foot Mechs. With their army almost complete, the Foot sends a mech to find and destroy the Turtles. When this Foot Mech attacks his family, Splinter devises a counterattack with the aid of a powerful warrior in a tricky alliance.