This episode starts out with two hikers climbing messas in Nevada. When one of them mysteriously dissapears on the messa right next to a Nana war machine the millitary gets involved, and so does the Justice League. Its the military's job to evacuate the three nearest cities, while the Justice League try to defeat this menace.
The machine produces different defense systems like little machanical spiders and large mechanical tigers. When the Justice League destroys one it rebuilds itself! In this episode it shows many smaller characters such as, Huntress, Booster Gold, Golden Knight, Vixen, Atom Smasher, and The Atom.
They try and hold off the nanobots Superman goes to recruit Ray Palmer (Atom) to help because he is an expert on nano technology.He shrinks himself and enters the war machine. He tries to smash the controls but cant, they are to powerful to crush. Then The Atom plugs an artery giving the Dark Heart inside controlling a heart attack. In the end the war machine exploded and the Justice League saved the day again.