The Turtles become embroiled in the turf war as they face off against the Foot, headed by the Elite Guard, while a mob-funded attack robot created by Baxter Stockman and the Purple Dragons, led by Hun, besiege the Foot's rundown headquarters. To make matters more complicated, a ninja from Japan named Karai enters the fray, though her intentions are ambiguous. At her mercy, the Turtles have no choice but to bargain with her.