Batman: Zero Year Duke's first appearance is as an unnamed child, fishing in the derelict
Gotham City. He is approached by thugs wanting to take his food, who are stopped by the sudden appearance of Batman. Duke tells him that the
Riddler claims that he is dead, to which Batman replies that it means he will not see him coming.
Batman: Endgame The Joker releases a deadly pathogen on Gotham City that mimics his laugh gas on a much larger scale. In the ensuing pandemonium, he kidnaps the Thomas family due to their connection with Bruce Wayne. He sets up an elaborate stage on which to reenact the night the Waynes died, even going as far as to use an infected
Joe Chill, the man who originally killed his parents, to emotionally torture Bruce. Duke is narrowly saved by Batman, but is forced to leave his parents behind to an infected mob.
We Are... Robin Several months later, Duke is in the foster care system. He rebels as he feels frustrated by the lack of care and empathy the city has been granting to the Joker's victims, resulting in his parents still being missing. Alongside this, Gotham City appears to have been abandoned by Batman.
Alfred Pennyworth has secretly been supplying teens fighting back against crime and corruption with Robin insignia and instructions via an app called "The Nest", starting the group known as We Are Robin. After assisting the group, Duke is approached by Alfred, disguised as a police interrogator. He encourages Duke to take his life into his own hands and to fight for the fate of the city, offering him help finding his parents if he helps stop a cult from detonating bombs around the city. Duke accepts, making him an unofficial Robin. He leads part of the group to the bombs inside a train station. While the rest of the group is above ground fighting off the cultists, they are able to defuse one bomb. As they debate about how to defuse the second, they are sent a message from The Nest, telling them to give up and get on the next train. Meanwhile, above ground the GCPD reveals a "new" Batman, who is simply
Jim Gordon in a robotic suit. He is instructed to treat the Robins as criminals. One member, Troy, stays behind, and attempts to defuse the bomb in the same manner as the first one, causing it to detonate and kill him. Duke and his new friends are devastated, and become suspicious of The Nest, until Alfred provides them gear, and draws on their individual experiences to encourage them to keep fighting for their city. After the events of
Robin War, most Robins go back to their normal lives. Duke resumes his search for his parents and finds that they were permanently damaged by the Joker virus. Meanwhile, John "Smiley" Bender Jr., a teen with
Möbius syndrome, whose parents forced him into surgery that left him with a permanent smile, kills them after getting out of juvie. Holding the Joker as an idol, he starts a gang and begins terrorizing Gotham. Smiley invades Duke's school, forcing him and his friends to take action. After taking him down, the group is approached by Alfred and renounce being Robins, deciding to rely on themselves and each other.
Robin War Shortly after Troy's death, a Robin outside of Duke's group accidentally kills a robber and police officer. Combining the two with public push, the Robin laws go into effect, making it illegal for teens to wear the Robin colors and insignia. These events were engineered by the
Court of Owls, as the councilwoman who headed the legislation, Noctua, wishes to earn a place in the society. Duke hosts a meeting of the remaining Robins, calling for whoever accidentally committed the crime to come forward. However the real Robin,
Damian Wayne, crashes the meeting. Objecting to the use of his title while he was away, he challenges the Robins to prove themselves in a fight against him. The commotion is noticed by the GCPD, who send "Batman" to deal with them. He is quickly struck down by Damian, but before the fight can resume,
Red Hood and
Red Robin put a stop to it. They calm Damian down and call the first Robin,
Dick Grayson. Travis, one of the Robins, tells Duke that he was the one who killed the officer and robber. Duke seeing that it was an accident and that Travis is burdened by the guilt, encourages him to turn himself in and Travis agrees. While on his way, Travis is killed by a
Talon to sow more public unrest. The official Robins train the group. Despite having faked his death and using a face changer, Duke recognizes Dick Grayson and reveals this during a training session. Duke and his friends are chosen as the best of the group, and are taken on a mission to try and get information. However, Dick has been feeding information to the police, as to have the Robins arrested and safe from the Court of Owls. The original Robins, with help from Duke and his friends, break out and free the rest of the Robins. They tell the others to go home, as the Court of Owls is too deadly of an enemy for them. Thanks to information from Duke's friend Riko, they make their way to Gotham Academy. On the way, Damian sneaks away and is manipulated into joining the Court to protect Gotham. He, alongside several Talons, fight against the others once they reach Gotham Academy, seeming to take them out with ease. Duke refuses to believe that Damian has genuinely joined the Court, getting back up to continue fighting him. He calls Damian by name, saying that he knows of Bruce Wayne's amnesia as the result of sacrificing himself, and how Damian does not need to live up to that. This causes Damian to snap out of the Court's manipulations. The Robins that went home see the destruction throughout the city. They decide to rally once more and the tides turn against the Court, temporarily sending them back underground.
Batman Vol 9: Bloom After
Robin War, the villain
Mr. Bloom begins distributing experimental devices that give the user powers, but are likely to kill their host. After overhearing a conversation between Bruce and Jim Gordon, Duke becomes drawn to the mystery. He steals a neutralized device given to Bruce, as Bruce is reluctant to be involved in the case. He first shows the device to his older friend Daryl Gutierrez, a tech genius working as an engineer for the
GCPD, who is unable to identify it. Duke turns to other sources, tracking a trail to the
Penguin's
Iceberg Lounge. He finds a book containing information on Penguin's investigations on Bloom. The Penguin and his gang find Duke in the study, nearly capturing him. He barely escapes, only to be seemly apprehended by guards outside. Until Bruce Wayne takes them down. Bruce had discovered the device missing, and since Duke had used the Fox Center's computers for his research, was able to deduce what he was doing and follow him. He expresses concern for Duke, he continues to press when Duke tries to avoid the conversation, asking why Duke has treated him coldly. Duke becomes upset, as he is aware of Bruce's former identity as Batman while Bruce is not. He tells Bruce that he does not take a real look at his life, saying that his denial is based in selfishness. He tells Bruce that anyone can be who he is now, but in his old life only he could be him, and that he used to inspire the whole city. He continues with his speech, causing a spark in Bruce's memory when he saves Duke from an incoming train. Duke, feeling no better, tells Bruce to stay away. Duke tells Daryl that it almost made him give up hope and vigilantism entirely, however, he went over the evidence he stole from the Iceberg Lounge one last time, and noticed that it contained the names of the nominees for the grant that Daryl won years before. He asks Daryl what is going on, Daryl snaps and his form begins to mutate to where he looks eerily similar to Bloom. He reveals that he was the "original" Bloom, having initially created the devices after
Zero Year, believing that with powers people would band together to protect each other. However, his first test with his cousin yielded fatal results, which made Daryl burn the remaining devices. After Batman's disappearance following
Endgame, he turned towards his experiments again. This time using unidentified and near death patients. There was only one success, who became horrifically deformed, and slaughtered the other patients. The patient somehow recognized Daryl as the source of what happened to them, and decided to take the Bloom moniker, along with the rest of the devices. Daryl insists that he can stop Bloom and perfect the devices. Duke tries to reason with him, saying that powers are not necessary and all you need is good people. Daryl mocks him and the
Robin movement. He moves to take and dispose of a Robin pin that Duke gave him, but Duke takes advantage of his distraction to incapacitate him and take control of the airship. During Daryl's confession, Bloom has begun widespread havoc across the city. Introducing handpicked convicts they have used the devices on. They inform the populace that they have hidden devices all over the city, and that they now have a programmed thrall to encourage their use, as the use of them makes Bloom stronger. Along with sabotaging the GCPD's atom collider, which could cause a black hole. Duke directs the airship to where Bruce, having remembered being Batman, is struggling to hold them off. Duke uses the high powered magnets in the ship to grab onto Bloom. The more Bloom struggles, the stronger the magnets get. This also disables the thrall, leading to people removing their devices and diverting power from Bloom. Gordon uses a dampener on the collider, and the resounding shock wave kills Bloom. Duke is approached by Bruce, who offers to train him as an official vigilante.
All-Star Batman Duke becomes an official member of the Batman Family. After accepting Bruce's offer to train under him, Duke moves into Wayne Manor and begins working alongside all of Gotham's vigilantes. He is a heavy feature in
All-Star Batman, assisting Bruce in dealing with
Two-Face,
Victor Zsasz,
Hugo Strange, and
Mr. Freeze.
Dark Days: The Road to Metal Leading into the events of
Dark Nights: Metal, while Batman was on a mission related to the mysteries surrounding Nth Metal, Duke was tasked to guard the
Batcave. This led to a confrontation with the Green Lantern,
Hal Jordan, who had been sent by the
Guardians of the Universe to investigate sinister cosmic omens pointing to that location. Duke joined the investigation and together they found a secret level of the Batcave. In the hidden level were various clues that Batman had collected and stored over the years related to Nth Metal, as well as a prison holding the Joker. The Joker taunts the heroes into freeing him using the secrets he has learned from the cave. He reveals the origins of
metahumans, and that Batman recruited Duke because Duke and his mother are metahumans who are connected to a "Dark Crisis". In the chaos of their fight, The Joker destroyed Batman's machines before escaping the two heroes and vanishing from the cave entirely. Batman arrives and confirms there is some truth to what the Joker said. Duke's powers begin to manifest, and using a Green Lantern ring and the power of the Shazam's dagger, the trio unknowingly set off the chain of events leading to the invasion of
Barbatos and the
Dark Multiverse.
Batman & The Signal After studying under Batman for over a year, Bruce surprised him with his very own base of operation and an upgraded suit; congratulating him for completing his training. Duke took the codename Signal and became the daylight protector of Gotham, recruiting his former Robin gang teammates Riko Sheridan and Izzy Ortiz for technical support. Duke's first solo mission as Signal was to investigate the sudden spike in dead metahuman bodies being discovered all throughout The Narrows. This led Signal into conflict with The Null, a metahuman from the Arkham Juvenile Detention Center aka "Juvie Arkham". After defeating Null, Signal decided to investigate further into Juvie Arkham, which had once been the old Gotham solarium before being reworked to house metahuman delinquents. Duke used his Ghost Vision to infiltrate Juvie Arkham and walked straight into an ambush. Luckily, Detective Aisi arrived just in time to help Signal make a narrow escape. Later, Signal met up with Aisi to compare notes. Using his photokinetic sight to examine a tissue sample from one of the dead metahumans, Signal discovered trace amounts of Nth metal embedded in the skin of the sample. The metal and the sample appeared to be react Duke but also to something in the air. That is when Signal noticed a strange solar pattern radiating from the Gotham Proper housing project. Signal theorized someone must be using Gotham Proper to direct supercharged solar energy toward different sections of the city like a sundial, creating unstable metahumans across The Narrows. Duke returns to the Batcave to bring his new theory to Bruce when the bat-computer is hijacked by someone calling himself Gnomon. He shows them a live broadcasts of The Narrows overrun with innumerable metahumans, all chanting Duke's name, as they wreak havoc across the city. Gnomon reveals that he is the one creating the metahumans. Gnomon claimed to have created the metahumans for Duke as a gift, asking Duke to join him. Duke and Bruce head out as Batman and Signal to stop the villain. When Batman and The Signal arrive on the scene the Batfamily are spread thin. The duo split up, with Duke making his way to confront Gnomon at Gotham Proper. Signal arrived at Gotham Proper just as Detective Aisi and the GCPD cleared the area, and the two enter the building to confront Gnomon together. In the solar observatory, Gnomon reveals he is Duke's father and that years ago his mother, Elaine, fled to Gotham to hide Duke from him. Signal can sense everything Gnomon says is true due to their genetic connection but summons the resolve to stop Gnomon anyway. Signal, with the help of Detective Aisi, manages to defeat Gnomon, who manages to escape capture.
The Outsiders Some time after the events of
Justice League: No Justice, the villain Karma lured Duke into a trap that blew up a building, killing a civilian, in the process. This attack left Duke in critical condition and kicked off a series of terrorist attacks by the villain to isolate Batman him from his allies. Batman responded by re-forming the
Outsiders and conceded leadership of the group to Black Lightning, fearing he might compromise the team. Enlisting the help of Katana, Cassandra Cain, and a recovered Duke, the Outsiders took down Karma and officially forming the newest iteration of the Outsiders. Still traumatized from the Karma attack, Duke and the Outsiders are involved in a proxy war between Batman and
Ra's al Ghul over the metahuman Sofia Ramos. Ra's manipulates the Outsiders, planting the cyborg Kaliber in their ranks to get to Sofia to keep them busy and disrupt their team. With Katana and Black Lightning preoccupied by Sofia Ramos and Kaliber, Duke is captured by Ra's' acolyte
Ishmael. Ishmael reveals he was reborn in the Lazarus Pit, changing his initial ability to steal metahuman powers into the ability to evolve and change metahuman powers. Ishmael and Ra's see potential in Duke and plan to use Ishmael's powers to evolve Duke's powers for Ra's ends. Ishmael chained, beat Duke and modifies his metahuman abilities, allowing him to manipulate darkness as well as light.
Death Metal During the events of
Death Metal, Signal, Orphan, Spoiler, and Red Robin fight to reclaim the Narrows in Gotham City. Guarding the area is Quietus, an amalgamation of Duke Thomas, Ra's al Ghul, and Batman originating from a universe in the Dark Multiverse. Quietus initially overpowers Duke and his team, using the waters of the Lazarus Pits to torture Duke with twisted visions of his history from the Dark Multiverse. Duke perseveres and defeats Quietus, reclaiming the Narrows. ==Powers and abilities==