The Watchtower is an orbiting satellite, and the true headquarters of the Justice League. League members are transported to the Watchtower from the Hall of Justice and the Cave. The Watchtower has sensors that can detect immense energy surges on the surface of the planet, but does not have any weapons systems.
When the Justice League decided to secretly establish an orbital base, they turned to the Green Lantern Corps for help. They gave the League a decommissioned Green Lantern base station that had been constructed from an asteroid. Hal Jordan and John Stewart towed it into Earth's orbit, and the station was modified to suit the League's needs, including the installation of Zeta-Tubes. The League started operating out of the Watchtower after their base in Mount Justice was compromised. Its existence has been kept from public knowledge,with the aid of cloaking capabilities.
With the Light still in control of the Justice League, the Team had to infiltrate the satellite via another way. They used the Bio-Ship, and via a makeshift dock, entered. With the help of cure-tech, they negated the effects of the Starro-tech.
The Team celebrated the new year aboard the Watchtower and discussed the past events with the League.
In the Watchtower, John Stewart explained about Lobo and the Kroloteans. Adam Strange explained about Rann and showed a tech which traces Kroloteans. Nightwing decided that the Team went after the remaining Kroloteans and investigate on Rann.
Batgirl presented recordings of the walls of an ancient Bialyan temple to Doctor Fate, Zatanna, Robin and Nightwing. Fate translated the hieroglyphics, revealing an ancient ritual to cleanse a scarab.
Following the destruction of Mount Justice and its memorial grotto on March 23, a memorial grotto was set up on the Watchtower.
Captain Atom hailed the Warworld to attempt negotiations, to no avail. Aquaman and Nightwing monitored from the Watchtower as Captain Atom joined other Leaguers in a frontal assault on the Warworld, while the Team infiltrated the vessel.
The Watchtower May 26, post-07:35EDT
After the Warworld launched a saturation missile attack, Aquaman used the Watchtower's systems to estimate the effectiveness of Earth militaries' defenses.
Nightwing congratulated the Team from the Watchtower after they succeeded in disabling the Warworld.
Following a successful mission, Nightwing officially handed command of the Team back to Aqualad. Shortly after, a boom tube opened, depositing the unconscious bodies of Leaguers who had been guarding the Warworld's key chamber.
Lucas Carr coordinated the twenty squads of heroes as they simultaneously attacked and disabled twenty MFDs. By the time all twenty MFDs were down, several heroes had returned to the Watchtower, including Kid Flash. When Blue Beetle reported detecting a twenty-first MFD at the North Magnetic Pole, and Flash and Impulse reported it to have already gone chrysalis, Kid Flash zeta-ed out to help.
In the mission room, several Leaguers watched G. Gordon Godfrey's report on Secretary Tseng's resignation and Godfrey's proposal of Lex Luthor as his successor. Captain Atom turned over the chairmanship of the League to Black Canary. Nightwing informed Aqualad of his decision to take a leave of absence from the Team.
In the memorial garden, Tigress and Kid Flash discussed their new identities, Robin and Wonder Girl welcomed Static to the Team, and Miss Martian and Superboy talked about Tim and Cassie's new relationship. The discussions were interrupted when Aqualad summoned everyone to the mission room.
Batman informed the assembled Team that they would now operate out of the Watchtower alongside the League. The Leaguers left them to carry on, and Aqualad handed out mission assignments.
The Justice League, the Team, the Outsiders and Batman's team met at Nightwing's request. After he officially revealed the activities of the "Anti-Light" and its members resigned from their leadership positions, Black Lightning was elected as the League's new leader.
Superman and Cyborg had lost contact with Mars following the destruction of their Zeta-Tube. Martian Manhunter had arrived safely on the Watchtower and deduced that something wrong had occurred. Manhunter requested for Cyborg to boom tube them to Mars, but without a signal, it would be too dangerous. Superman contacts Steel to bring the Javelin. Em'ree J'onzz contacts the Watchtower, relieved to learn her uncle is alright and informs the Leaguers of the explosion. Cyborg attempts to lock on to their signal until their connection is cut off by the destruction of the M'arzz-Earth Communications Satellite. Steel informs them the Javelin won't be arriving back for a few days. Martian Manhunter realizes that M'gann, Conner and Garfield are on their own to deal with the mystery.
Superman was relaxing in the gardens of the Watchtower and spoke to Lois on the phone. He assured his trust in Conner, M'gann and Garfield to handle the current troubles on Mars and reassured that himself and Martian Manhunter would soon be joining to help them. He also expressed hope they might make in time for Conner and M'gann's wedding. The discussion moved on to their son, Jonny Kent who was having difficulty potty training and began to shows of developing Kryptonian powers. Superman became frantic when Jonny began to cry and Lois claimed his eyes were glowing red, but could not confirm when the call was cut off. Superman asked Cyborg to open a boom tube.
In the weeks following Superboy's death, a hologram of him has been placed in the memorial garden beside Kid Flash. Artemis stands before the holograms of Wally and Conner, silently mourning the loss of her fallen friend.
Dick and Kaldur visited Conner's memorial. Kaldur began to express his grief, admitting he still had trouble coming to terms with Conner's death in spite of everything they've done to honor him. Dick tried to convince Kaldur to give himself a break, realizing he never gave himself the chance to grieve Wally or Tula's deaths and instead has always been the rock holding everyone together. Kaldur refused, assuring he will be fine, and left the grotto to prepare for the upcoming conference in Poseidonis.
Black Canary had a therapy session with Zatara, discussing his time trapped inside the Helmet of Fate for the last decade. Zatara tried to assure that his faith in God and his daughter is what kept him alive, until he finally broke down and cries with Canary comforting him.
Miss Martian arrived at Black Lightning's request to make psychic contact with the Kaizer-Thrall, learning he is meta-human trafficking victim, Danny Chase. Prince J'emm J'axx contacted them shortly after, revealing that Superboy may still be alive. The Watchtower was moved above the Zeta-Shield to allow J'emm and Phantom Girl to Zeta aboard. Phantom Girl was introduced and explained how she saved Superboy and accidentally sent them both to the Phantom Zone, including how Superboy has fallen under the influence of Dru-Zod. The group hatched a plan to rescue Superboy with help from Orion.
The first JLA base to use the name "Watchtower" was built on the moon's surface during the Grant Morrison run of the JLA series. Earlier bases in Earth's orbit were called the Justice League Satellite; they returned to a satellite after Infinite Crisis.
This marks the fifth animated appearance of the Watchtower. It appeared in the DCAU, there were two: one in Justice League (which was destroyed in the finale) and a new model in Justice League Unlimited. It also appeared in The Batman, Justice League: Crisis on Two Earths and Batman: The Brave and the Bold