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 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
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 The episode ends with Batman joining J'onn on