Batman: Arkham Knight

Batman: Arkham Knight is an action adventure game developed by Rocksteady Studios and the fourth installment in the Batman: Arkham series. Taking place nine months after the events of Batman: Arkham City, the story follows Batman as he fights against Scarecrow, who has caused a mass evacuation of Gotham City and united his enemies, as well as the enigmatic Arkham Knight, in a bid to destroy the Dark Knight once and for all.

Gameplay
Batman: Arkham Knight is an open-world action-adventure game, using a third-person adjustable camera. Many gameplay elements from previous titles return, including the FreeFlow combat system, gliding mechanics, and wide array of gadgets.

Combat has been expanded, allowing for Batman to perform environmental takedowns and temporarily use melee weapons against enemies. In certain sections of the game, Batman can fightside along allies (either Nightwing, Robin, or Catwoman) and seamlessly switch control to said ally during combat. New enemy types have been introduced: medics can revive enemies or imbue with electrical charges, brutes must be stunned to make them vulnerable to attack, and sword-wielding enemies can use acrobatics and faster attacks.

In Predator Mode, Batman can now use the "Fear Takedown", allowing him to take out three enemies at a time in quick succession: this takedown can be reused once a Silent Takedown is performed. The new Voice Synthesizer gadget can be used to lead enemies into traps, the Disruptor can be used to disable or sabotage guns, and the Remote Hacking Device can activate parts of the environment to take down enemies. Conversely, enemies now have access to sentry guns, remote drones, and will disable vents if they catch Batman inside. Enemies with gattling guns take longer to finish off, and cannot be finished off with stealth takedowns.

Batmobile
The game marks the introduction of the Batmobile as a drivable vehicle. The Batmobile is also able to enter a tank-like form.

Plot
The story begins nine months after the events of Batman: Arkham City. With the Joker's death, Gotham City's crime rate has fallen drastically. However, the night before Halloween, the super-villain Scarecrow releases a sample of his latest fear toxin into a diner, causing the occupants to tear themselves apart in fear-induced hallucinations. With his example made, Scarecrow threatens to unleash the toxin again on Halloween, this time on a much larger scale. The civilian population of Gotham is evacuated within 24 hours, leaving behind only criminals, an overwhelmed police force, Batman, and his allies.

Following a tip from the GCPD, Batman finds and apprehends a man driving a military vehicle. Taking the man's vial of fear toxin and sending it to his ally Oracle for analysis, Batman learns that Scarecrow has a safe-house in Chinatown. He arrives at the safe-house to find Poison Ivy being detained by men in military attire. After Batman defeats all of the men, Poison Ivy reveals that Scarecrow recruited all of Batman's enemies in order to take out Batman one and for all. Poison Ivy was the only one to decline, leading Scarecrow to capture her. After bringing Ivy to GCPD, Batman meets with Oracle, reverse engineering the fear toxin to determine its site of production: the ACE Chemicals Plant. Before Batman and Gordon can enter the plant, they are stopped by a man in a military helicopter, who destroys part of the bridge. Batman enters the facility alone to find that Scarecrow and the assailant (whom Oracle can only identify as "the Arkham Knight") have built an army for a full-out assault on Gotham. Venturing further inside to rescue the remaining factory workers, he learns of Scarecrow's plans to unleash a bomb that will cover the entire eastern seaboard in Fear Toxin. Batman manages to reach Scarecrow, who tells him that he has kidnapped Oracle before escaping. Knowing the bomb can't be stopped, Batman quickly produces a neutralizing agent to contain the blast to ACE Chemicals. While he is deploying it, he is exposed to Scarecrow's toxin and has a hallucination of Joker.

Through a flashback, it is revealed that five of the people infected with Joker's blood, including Batman, were not treated in time, and have begun mutating into Joker. The only hope for a cure lies in Henry Adams, who appears to be immune to the mutation. Batman has quarantined the other four infected in his base at Panessa Film Studios, and has hidden his condition from his team. The fear toxin now causes Joker to appear as a lingering mental projection, taunting Batman and manipulating his perception of the world. Batman informs Gordon about Oracle's kidnapping, and Gordon angrily storms off when Batman reveals Barbara's involvement with him. When Tim Drake/Robin, who is working on the cure and in a relationship with Oracle, questions Oracle's silence, Batman hides her kidnapping to keep him focused.

Batman follows the Arkham Knight's trail across Gotham to a pair of airships owned by pharmaceutical magnate Simon Stagg. Aboard the airships, Batman learns that Stagg worked with Scarecrow to perfect the Fear Toxin, as well as a device dubbed "Cloudburst". Batman corners Scarecrow, but a Joker-induced hallucination allows Scarecrow to expose him to Fear Toxin again, allowing Joker to briefly take control of his body. In the aftermath, Scarecrow and the Arkham Knight escape with the Cloudburst. When Batman comes to, Scarecrow broadcasts a message revealing Oracle's location as the Chinatown safe-house. Batman races to the safe-house, and is forced to watch Oracle be exposed to the Fear Toxin and subsequently kill herself in terror. While grieving Oracle's loss and blaming himself for her death, Batman is warned by Alfred that the Cloudburst is a dispersal device for the Fear Toxin. Ordering Alfred to run scans for the Cloudburst, Batman heads to GCPD and convinces Poison Ivy to help him create a Fear Toxin antidote. With Ivy's guidance, the two restore a pair of ancient trees in order to mass produce the antidote.

As Batman and Alfred continue searching for the Cloudburst, Harley Quinn invades Panessa Studios in order to steal the Joker infected for herself. Batman rushes to Robin's aid, and the two work together to capture the infected. However, Batman suffers hallucinations of Jason Todd, the previous Robin, who was captured and killed by the Joker. After detaining Harley and the last of the infected, he and Robin return to the cells. To their horror, they find that Henry has succumbed to the infection, and killed the other infected in order to "purify the Joker gene pool". However, upon realizing Batman's condition, Henry kills himself, knowing Batman would make the better Joker. Coming to the same realization, Robin implores Batman to lock himself away before the transformation takes hold. However, unwilling to risk Robin's life against Scarecrow, Batman imprisons Robin instead.

The Arkham Knight activates the Cloudburst, engulfing Gotham in Fear Toxin. Batman destroys the device, but Poison Ivy sacrifices herself to cleanse the city. Batman finds Gordon in Scarecrow's clutches at a construction site, where he comes face-to-face with the Arkham Knight. The Knight reveals himself to be Jason Todd, having survived the Joker's torture but brainwashed into believing that Batman left him to die. Batman manages to get through to Jason, but the latter disappears shortly thereafter. Upon rescuing Gordon, Batman goes to confront Scarecrow only to be reluctantly betrayed by Gordon. With Barbara being alive (her death being a Fear Toxin hallucination) and held hostage, Gordon manages to free both Batman and Barbara before being taken again by Scarecrow's forces.

Development
Development on Batman: Arkham Knight began soon after completion of Batman: Arkham City.