During the invasion, even Gotham's villains—including The Joker, Penguin, Bane, and Mr. Freeze —fight alongside the GCPD to defend their city.
The robotic alien hive-mind known as has launched a full-scale attack on Earth. While Martian Manhunter (J'onn J'onzz) warns of the threat, Batman initially tries to stop the invasion alone to protect Batgirl and Robin from danger. [S4E13] The Joining: Part 2
Batman and J'onn attempt to infiltrate Wayne Industries to use its satellites to disrupt the Joining's signal. While Martian Manhunter (J'onn J'onzz) warns of the
The episode ends with Batman joining J'onn on the Watchtower space station, where he meets other heroes: Green Lantern, The Flash, Hawkman, and Green Arrow . " The Joining: Part 2 " is the
" The Joining: Part 2 " is the season finale of The Batman (2004) Season 4, originally airing on May 5, 2007. The episode concludes the high-stakes alien invasion arc and marks Batman's official transition from a solo vigilante to a member of the Justice League.