Warning! Spoilers for Justice League Unlimited - Epilogue
Crimefighting brothers Terry and Matt McGinnis are Gotham City’s future dynamic duo as Batman and Robin, but they are also Bruce Wayne’s secret sons. Although it wasn’t an explicitly stated plot point in the comics, the DC Animated Universe serves as context for their biological heritage.
As DC Comics continued the story of Terry McGinnis’ Batman Beyond, the recruitment of his brother Matt into the bat family felt like a natural extension. When he became the new Robin, it was exciting territory for the comics iteration to explore, since it hadn’t happened in the animated series. Breaking into the Batcave and smashing the glass case containing Damian Wayne’s fashionable Robin costume, Matt stole the suit, homaging Terry’s origin story. Training to be the new Boy Wonder without Bruce or Terry’s awareness, he soon earned the title. The brothers’ partnership was a fun subversion for what fans expect from the dynamic duo, but the DC Animated Universe offers another subversion.
When Justice League Unlimited’s episode “Epilogue” revealed that Amanda Waller had secretly altered Warren McGinnis’ DNA to produce Bruce Wayne’s son, Terry’s world was turned upside down. The twist had massive implications for the DCAU, but it hasn’t been properly considered in the ongoing comic book iteration of Batman Beyond. Although Bruce already had a biological son in Damian Wayne, he is also the secret father of Terry and Matt McGinnis, the future Gotham’s Batman and Robin. While the comics differentiate from the traditional DCAU in many ways, such key plot points have been maintained. It’s fitting that Bruce would be the literal father of the second generation Batman and Robin.
Since Amanda Waller’s account of her plan to create a second Batman wasn’t fully explained, it could also be revealed that Matt is only Terry’s half-brother. However, given the way in which Matt resembles his brother in stealing the Robin costume and taking things into his own hands to join him in the war on crime, there’s a good chance they are both Bruce’s kids. By this logic, Matt had aspired to be like his half-brother, Damian, as he watched security recordings of his training sessions alongside Bruce. It would probably intimidate criminals in Gotham that the new dynamic duo are the legendary Dark Knight’s offspring.
Many Batman fans still hold Epilogue to be one of the best stories told within the DCAU. It would be compelling for the episode to be expanded in the comics, with both Matt and Terry coming to the realization that Warren isn’t their actual father. Although Terry would continue to feel the weight of the twist, Matt might be quick to embrace being Batman’s son, and the former Robin’s half-brother.