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.
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 . [S4E13] The Joining: Part 2
Batman and J'onn attempt to infiltrate Wayne Industries to use its satellites to disrupt the Joining's signal. The robotic alien hive-mind known as has launched
" 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. Batman and J'onn attempt to infiltrate Wayne Industries
During the invasion, even Gotham's villains—including The Joker, Penguin, Bane, and Mr. Freeze —fight alongside the GCPD to defend their city.
With the help of Lucius Fox and Alfred, Batman successfully activates the satellites, causing the Joining’s ships to crash and shutting down the invasion for good. Key Characters & Cast Voice Actor Bruce Wayne / Batman Rino Romano Dick Grayson / Robin Evan Sabara Barbara Gordon / Batgirl Danielle Judovits Alfred Pennyworth Alastair Duncan Martian Manhunter Dorian Harewood Lucius Fox Louis Gossett Jr. Major Impact & Trivia