Bruce discovers that Wayne Industries is distributing alien technology across the world and gains the aid of a mysterious ally, who warns him of an alien race threatening to conquer Earth. Meanwhile, Batman begins to wonder whether he'd be better off without Batgirl and Robin.
Tropes for this episode include:
- Brick Joke: Seeing that John has telekinesis, Bruce asks how many pounds he can carry; John says he could carry Bruce and his best friend. When escaping the Wayne Industries factory with Lucius, John says "I told you so."
- Hover Board: A recovered crate for evidence contains a mini-saucer that can fly, which Robin uses as such.
- I Work Alone: Batman considers that he had more success when he fought solo.
- Marilyn Maneuver: As Batman chases after the Martian Manhunter in the Batwing, they fly through Gotham at high speeds and a woman in a black dress has to keep it down when they zoom past.
- Mysterious Past: Detective John Jones worked in Denver before joining the Gotham PD, but there's nothing before Denver. That’s because “John Jones” is really J’onn J’onzz, aka the Martian Manhunter.Bruce: It's like he didn't exist before then.
- The Reveal: Lucius Fox knows Bruce Wayne is Batman and the Martian Manhunter warns the latter that an alien race known as the Joining is planning to conquer Earth using ships created from Wayne Industries technology.
- Robot Me: The Lucius that Batman has been interacting was a robot for the Joining.
- Secret-Keeper: Lucius is one of the people protecting Batman's Secret Identity.
- Wham Line: "Detective John Jones". That's right, J'onn J'onzz, the Martian Manhunter, has arrived.
