Krang's computers detect an alien metal on the surface of the Earth, so naturally, Krang sends Shredder, along with an Alien Metal Detector, to the surface to find it. Meanwhile, the Turtles realize that it is National Sensei Appreciation day and they must go out and buy Splinter a present. Later, at the pawn shop, the Turtles, dressed in their trench coats and fedoras, purchase an old ninja sword. As they leave, Shredder, Rocksteady and Bebop arrive, via their Transport Module, at a Laundromat across the street. Krang's Alien Metal Detector begins 'sounding', indicating that what they seek can be found in the pawn shop -- but when they arrive, the signal weakens. Shredder is convinced that the 'Four Men' who left the shop before they arrive, possess the 'Alien Metal'. When the pawn shop proprietor tells him that they purchased a sword -- Shredder is even more convinced. (thetvdb.com)