"Apocalypse Rising" is the 99th episode of the television series Star Trek: Deep Space Nine, the first episode of the fifth season.
Having learned from Odo that a Changeling has taken Gowron's form and is now in control of the Klingon empire, Sisko is ordered by Starfleet Command to expose the imposter. He, Odo, O'Brien, and Worf must get close enough to the false Gowron to expose him as a Changeling, and must pose as Klingons to do so. Julian Bashir is called upon to surgically alter them to that end (even Worf is altered so that his cranial ridges are different, to keep him from being recognized). Sisko is also given four metal spheres which, when activated, will emit radiation which will force any nearby Changeling to revert to its natural gelatinous state.
Sisko calls upon Gul Dukat, who had previously captured a Klingon Bird of Prey, which Sisko hopes can get them to Ty'Gokor, the heavily guarded headquarters of the Klingon military, undetected. On board the Bird of Prey, Worf trains the humans to behave like Klingons, while Dukat creates Klingon identities for each of the four, adding them to a list of candidates that will receive the Order of the Bat'leth, which is awarded by Gowron himself. Arriving at Ty'Gokor, Dukat transports them to the surface and leaves them to fend for themselves, as they will be able to leave Klingon space freely if they succeed and the war ends, or will be executed as spies if they fail.
The four arrive at the Hall of Warriors, where the ceremony has already begun, and try to blend in as best as they can - they take anti-intoxicants in advance to survive a night of drinking Klingon bloodwine. Soon General Martok, second in command to Gowron, arrives, indicating that Gowron will arrive soon. The four scramble to set up their emitters, not without some difficulty. O'Brien then encounters a problem: Martok seems to recognize him, though he is able to convince Martok that they fought in a battle together. The four finally set up the emitters, and Sisko is called to receive his award. He attempts to activate the emitters, but is knocked to the floor by Martok, who has finally recognized them and has them thrown in a security cell.
Once they are alone, Martok confides to Sisko that he too believes that Gowron is an imposter. He says that Gowron ordered that the emitters be destroyed, but still agrees to help, saying that the only way to expose Gowron is to kill him. Martok then releases Sisko and his group and leads them back to the Hall of Warriors, but keeps Odo outside, saying he does not trust him. Worf proceeds to attack Gowron who insists on fighting him one on one, just as a real Klingon would. Martok wonders why Sisko does not shoot Gowron outright. Odo then points out something: Gowron called off his body guards and chose to stand to fight Worf in singular combat, thus showing Klingon honor. Changelings on the other hand, do not care for honor. Martok insisted that there would be no honorable combat, which is very uncharacteristic for a Klingon. Odo concludes that the Changeling is not Gowron, but Martok. Just when Worf is about to kill Gowron, Odo reveals the false Martok to the crowd, and the Klingons open fire, quickly destroying the Changeling.
Gowron then realizes that Odo had been falsely led to believe that Gowron was the Changeling, which would have led to Gowron's assassination by the Federation, thus allowing the fake Martok and the Founders to gain control of the Empire. Gowron also expresses his doubt that the war will end because Klingons do not simply turn from battle, but he does agree to a cease fire, and Sisko and his men are returned safely back to DS9.
The primary photography for the episode was conducted on Stage 18 at the Paramount Pictures lot which was used to represent the Klingon Hall of Warriors. The set featured statues 12 feet (3.7 m) high . Different styles of lighting were used in the Hall as compared to the Klingon prison in order to ensure that the two looked different. While there were flicker boxes installed in the Hall of Warriors set in order to give the appearance of fire, overhead blue lighting was used in the prison in order to make the set look much colder. Because of the size of the Hall of Warriors, cinematographer Jonathan West used bleached muslin to hide fluorescent lamps in the window treatments.
The bridge of the Bird of Prey was lit by overhead lights through patterned grids. One scene which featured over a hundred Klingons on scene was shot with only fifty extras. West used a split-screen effect filmed three times with a locked off camera each time which was then composited together in post effects.
"Apocalypse Rising" was nominated for two Primetime Emmy Awards, both for Outstanding Makeup and Outstanding Cinematography for a Multi-Camera Series for the work by Jonathan West.